How long is the flight from London Heathrow Airport to Illinois?

Departing from London Heathrow Airport to Illinois will take you 11h 10m. The distance from London Heathrow Airport to Illinois is about 3939 mi. Both multi-stop and direct flights can be found to your destination and back.

What are the cheapest airlines to fly from London Heathrow Airport to Illinois one-way?

One-way options have recently been found by users for as low as £262 on Scandinavian Airlines. Other airlines that offer cheap prices include JetBlue from £308 and Icelandair from £326 one-way.

In terms of precipitation, rainfall in Illinois ranges from 43.0 - 125.0 inches per month. August is typically the wettest month, when rainfall can reach 125.0 mm. January is typically the driest time to visit Illinois when rainfall is around 43.0 mm.

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -5.0 C).

What are the most popular routes from London Heathrow Airport to Illinois?

The most popular flight routes from London Heathrow Airport to Illinois are London Heathrow - Chicago O'Hare Intl, London Heathrow - Chicago Midway and London Heathrow - Lambert-St Louis.

What are the cheapest flights from London Heathrow Airport to Illinois?

Looking at all options, your cheapest flight can be booked for £339. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £333 on average, our data indicates £1,041 when flying from London Heathrow Airport to Illinois.

What are the most reliable airlines from London Heathrow Airport to Illinois?

Before booking your flight to Illinois from London Heathrow Airport, check out the most reliable airlines to get you to your destination on time: Austrian Airlines (88%), Brussels Airlines (88%), Lufthansa( 88%).

What are the most popular airlines that fly from London Heathrow Airport to Illinois?

When booking a flight from London Heathrow Airport to Illinois, you may want to consider flying on British Airways, Lufthansa or Finnair as they are the most popular for this route.

Can I find deals for flights from Heathrow to Illinois that include hotel bookings?

Yes. In addition to deals on Heathrow to Illinois flights, Cheapflights offers holiday packages that include both flights and hotel.

How can I find direct flights from Heathrow to Illinois?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Heathrow to Illinois.

Can I find deals for business class flights from Heathrow to Illinois?

Yes. Cheapflights offers flight deals from Heathrow to Illinois by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

£346+ Flights from London Heathrow Airport to Illinois

Q: How much does it cost for a return flight from London Heathrow Airport to Illinois?

Airfare is below average for this route at the moment. London Heathrow Airport to Illinois flights typically cost between £438 and £613 in February. The cheapest return flight price found within the last 3 days was £413 on Scandinavian Airlines (10 Feb-23 Feb).

Cheap flight deals from Heathrow to Illinois

Enter your travel dates to find the best prices.

Cheapest flights from Heathrow to Illinois
Explore the most affordable flight options available from Heathrow to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 December 2025.

Mon 29/1220:35LHR - ORD

1 stop26h 45mIcelandair

Tue 6/118:30ORD - LHR

1 stop19h 00mIcelandair

Deal found 27/12£645

Tue 30/1212:15LHR - ORD

1 stop11h 05mIcelandair

Sat 10/118:30ORD - LHR

1 stop19h 00mIcelandair

Deal found 28/12£683

Mon 29/1220:35LHR - ORD

1 stop26h 45mIcelandair

Wed 7/118:30ORD - LHR

1 stop19h 00mIcelandair

Deal found 28/12£684

Mon 29/1220:35LHR - ORD

1 stop26h 45mIcelandair

Fri 9/118:30ORD - LHR

1 stop19h 00mIcelandair

Deal found 28/12£685

Sat 27/1215:40LHR - ORD

2 stops34h 20mMultiple Airlines

Sat 31/117:53ORD - LHR

1 stop20h 17mMultiple Airlines

Deal found 27/12£695

Tue 30/1209:20LHR - ORD

1 stop15h 26mJetBlue

Mon 5/106:45ORD - LHR

1 stop32h 55mJetBlue

Deal found 27/12£761

Wed 31/1209:20LHR - ORD

1 stop15h 26mJetBlue

Thu 8/107:45ORD - LHR

1 stop17h 10mJetBlue

Deal found 28/12£776

Sat 27/1218:20LHR - ORD

1 stop31h 40mLOT

Sat 31/121:55ORD - LHR

1 stop13h 25mLOT

Deal found 27/12£780

Mon 29/1219:30LHR - ORD

2 stops30h 30mMultiple Airlines

Sat 10/119:20ORD - LHR

1 stop14h 40mMultiple Airlines

Deal found 28/12£797

Wed 31/1209:20LHR - ORD

1 stop15h 26mJetBlue

Sat 10/109:40ORD - LHR

1 stop17h 50mJetBlue

Deal found 28/12£806

Wed 31/1208:55LHR - MDW

2 stops19h 27mDelta

Tue 6/109:32MDW - LHR

1 stop17h 13mDelta

Deal found 27/12£919

Wed 31/1215:50LHR - MDW

1 stop23h 15mKLM

Tue 6/109:32MDW - LHR

1 stop17h 13mKLM

Deal found 27/12£948

Best flights from Heathrow to Illinois
Discover carefully curated flight deals from Heathrow to Illinois that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 29 December 2025.

Sun 10/508:50LHR - ORD

1 stop11h 10mBritish Airways

Mon 18/516:40ORD - LHR

1 stop11h 25mBritish Airways

Deal found 27/12£413

Thu 19/309:00LHR - ORD

1 stop13h 20mUnited Airlines

Sat 28/316:25ORD - LHR

Nonstop8h 20mUnited Airlines

Deal found 26/12£417

Sat 21/206:40LHR - ORD

1 stop16h 05mScandinavian Airlines

Sat 28/219:20ORD - LHR

2 stops17h 30mScandinavian Airlines

Deal found 28/12£418

Mon 12/113:35LHR - ORD

Nonstop9h 25mAustrian Airlines

Sun 25/121:05ORD - LHR

Nonstop8h 10mAustrian Airlines

Deal found 27/12£428

Thu 15/108:40LHR - MDW

2 stops15h 52mDelta

Thu 22/113:26MDW - LHR

2 stops12h 39mDelta

Deal found 28/12£437

Wed 11/206:30LHR - MDW

2 stops16h 59mVirgin Atlantic

Tue 17/213:28MDW - LHR

2 stops12h 37mVirgin Atlantic

Deal found 28/12£437

Fri 30/108:30LHR - PIA

2 stops19h 09mLufthansa

Fri 6/217:18PIA - LHR

1 stop11h 57mLufthansa

Deal found 27/12£679

Wed 11/214:10LHR - SPI

1 stop14h 04mMultiple Airlines

Wed 18/205:00SPI - LHR

2 stops20h 20mMultiple Airlines

Deal found 28/12£706

Wed 11/211:20LHR - SPI

2 stops16h 54mAmerican Airlines

Wed 18/205:00SPI - LHR

2 stops18h 50mAmerican Airlines

Deal found 28/12£766

Mon 13/408:50LHR - ORD

1 stop11h 10mBritish Airways

Sat 16/520:50ORD - LHR

1 stop10h 35mBritish Airways

Deal found 27/12£415

Sat 7/206:40LHR - ORD

2 stops16h 05mScandinavian Airlines

Sat 14/219:20ORD - LHR

2 stops17h 30mScandinavian Airlines

Deal found 28/12£421

Thu 8/113:35LHR - ORD

Nonstop9h 25mUnited Airlines

Wed 18/215:45ORD - LHR

Nonstop8h 10mUnited Airlines

Deal found 28/12£428

Tue 13/110:25LHR - ORD

Nonstop9h 20mAustrian Airlines

Tue 20/117:50ORD - LHR

Nonstop8h 05mAustrian Airlines

Deal found 27/12£428

Mon 26/108:40LHR - MDW

2 stops15h 56mDelta

Mon 2/212:46MDW - LHR

1 stop11h 39mDelta

Deal found 27/12£437

Wed 14/106:30LHR - MDW

2 stops21h 37mVirgin Atlantic

Tue 3/209:33MDW - LHR

2 stops15h 32mVirgin Atlantic

Deal found 28/12£437

Mon 12/107:55LHR - ORD

Nonstop9h 20mUnited Airlines

Mon 19/117:50ORD - LHR

Nonstop8h 05mUnited Airlines

Deal found 27/12£428

Wed 4/306:30LHR - MDW

2 stops17h 07mDelta

Wed 25/310:45MDW - LHR

1 stop14h 40mDelta

Deal found 27/12£437

Mon 12/107:55LHR - ORD

Nonstop9h 20mUnited Airlines

Wed 21/117:50ORD - LHR

Nonstop8h 05mUnited Airlines

Deal found 27/12£428

Wed 14/108:40LHR - MDW

2 stops15h 52mDelta

Tue 3/212:46MDW - LHR

1 stop11h 39mDelta

Deal found 28/12£437

Thu 22/113:35LHR - ORD

Nonstop9h 25mUnited Airlines

Sun 25/121:05ORD - LHR

Nonstop8h 10mUnited Airlines

Deal found 28/12£428

Mon 2/308:40LHR - MDW

2 stops16h 00mDelta

Sun 8/313:10MDW - LHR

2 stops13h 55mDelta

Deal found 28/12£437

Sat 17/107:40LHR - ORD

Nonstop9h 20mUnited Airlines

Sat 31/117:50ORD - LHR

Nonstop8h 05mUnited Airlines

Deal found 27/12£428

Wed 11/206:30LHR - MDW

2 stops17h 25mDelta

Tue 17/218:40MDW - LHR

1 stop11h 00mDelta

Deal found 28/12£437

Fri 30/108:40LHR - MDW

2 stops15h 56mDelta

Mon 2/212:46MDW - LHR

1 stop13h 04mDelta

Deal found 28/12£437

Tue 10/209:00LHR - STL

2 stops16h 27mUnited Airlines

Tue 17/213:11STL - LHR

2 stops15h 14mUnited Airlines

Deal found 27/12£442

Sat 28/206:30LHR - MDW

2 stops15h 44mDelta

Tue 10/317:40MDW - LHR

1 stop13h 00mDelta

Deal found 27/12£437

Wed 11/214:10LHR - SPI

1 stop14h 04mBritish Airways

Wed 18/205:00SPI - LHR

1 stop19h 55mBritish Airways

Deal found 28/12£709

Thu 15/109:00LHR - STL

2 stops16h 27mUnited Airlines

Sun 18/109:57STL - LHR

2 stops14h 23mUnited Airlines

Deal found 28/12£443

Wed 4/208:40LHR - MDW

2 stops15h 56mDelta

Sun 15/213:29MDW - LHR

1 stop13h 16mDelta

Deal found 27/12£437

Tue 10/209:00LHR - STL

2 stops16h 27mUnited Airlines

Wed 18/213:11STL - LHR

2 stops13h 14mUnited Airlines

Deal found 28/12£443

Direct flights from Heathrow to Illinois
Explore direct flight options from Heathrow to Illinois based on user searches, and compare prices and availability for your desired travel dates. Data last updated 29 December 2025.

Fri 9/110:25LHR - ORD

Nonstop9h 20mAustrian Airlines

Tue 13/121:05ORD - LHR

Nonstop8h 10mAustrian Airlines

Deal found 28/12£413

Wed 14/112:35LHR - ORD

Nonstop8h 50mBritish Airways

Wed 21/120:45ORD - LHR

Nonstop7h 40mBritish Airways

Deal found 28/12£414

Thu 15/114:10LHR - ORD

Nonstop8h 50mBritish Airways

Thu 22/120:45ORD - LHR

Nonstop7h 40mBritish Airways

Deal found 27/12£415

Thu 22/112:35LHR - ORD

Nonstop8h 50mBritish Airways

Sun 25/118:25ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 26/12£415

Sat 21/214:10LHR - ORD

Nonstop8h 50mBritish Airways

Sat 28/221:45ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 28/12£417

Wed 4/314:10LHR - ORD

Nonstop8h 50mBritish Airways

Tue 10/319:45ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 26/12£418

Wed 14/113:35LHR - ORD

Nonstop9h 25mMultiple Airlines

Tue 3/215:45ORD - LHR

Nonstop8h 10mMultiple Airlines

Deal found 28/12£420

Sat 10/110:25LHR - ORD

Nonstop9h 20mAustrian Airlines

Tue 13/117:50ORD - LHR

Nonstop8h 05mAustrian Airlines

Deal found 28/12£421

Sat 24/107:40LHR - ORD

Nonstop9h 20mAustrian Airlines

Sat 31/115:45ORD - LHR

Nonstop8h 10mAustrian Airlines

Deal found 27/12£422

Fri 13/207:25LHR - ORD

Nonstop9h 20mMultiple Airlines

Sun 22/221:15ORD - LHR

Nonstop8h 00mMultiple Airlines

Deal found 29/12£425

Sat 21/214:10LHR - ORD

Nonstop8h 50mBritish Airways

Sat 7/320:45ORD - LHR

Nonstop7h 40mBritish Airways

Deal found 27/12£426

Sun 12/409:45LHR - ORD

Nonstop8h 35mBritish Airways

Thu 30/417:00ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 28/12£426

Last-minute flights from Heathrow to Illinois
Discover last-minute flight deals from Heathrow to Illinois. Data last updated 29 December 2025 and is based on user searches.

Thu 8/112:05LHR - ORD

1 stop12h 32mMultiple Airlines

Wed 14/116:10ORD - LHR

1 stop18h 10mMultiple Airlines

Deal found 27/12£413

Thu 8/113:30LHR - ORD

1 stop12h 40mBritish Airways

Thu 22/116:14ORD - LHR

1 stop11h 26mBritish Airways

Deal found 27/12£420

Sat 10/111:30LHR - ORD

1 stop29h 40mLufthansa

Fri 23/117:50ORD - LHR

Nonstop8h 05mLufthansa

Deal found 28/12£424

Wed 14/111:05LHR - MDW

1 stop13h 27mVirgin Atlantic

Wed 21/113:49MDW - LHR

1 stop11h 16mVirgin Atlantic

Deal found 28/12£425

Thu 15/114:10LHR - ORD

Nonstop8h 50mBritish Airways

Thu 22/120:45ORD - LHR

Nonstop7h 40mBritish Airways

Deal found 27/12£415

Fri 16/107:25LHR - ORD

Nonstop9h 20mAustrian Airlines

Fri 23/121:05ORD - LHR

Nonstop8h 10mAustrian Airlines

Deal found 28/12£417

Mon 19/109:50LHR - ORD

1 stop15h 25mBritish Airways

Mon 26/118:45ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 28/12£416

Mon 19/121:05LHR - ORD

2 stops49h 40mScandinavian Airlines

Sat 14/219:20ORD - LHR

1 stop16h 20mScandinavian Airlines

Deal found 26/12£424

Thu 22/112:35LHR - ORD

Nonstop8h 50mBritish Airways

Sun 25/118:25ORD - LHR

Nonstop7h 50mBritish Airways

Deal found 26/12£415

Fri 23/112:15LHR - ORD

3 stops35h 37mMultiple Airlines

Fri 30/120:43ORD - LHR

3 stops32h 07mMultiple Airlines

Deal found 28/12£419

Sat 24/107:40LHR - ORD

Nonstop9h 20mAustrian Airlines

Sat 31/115:45ORD - LHR

Nonstop8h 10mAustrian Airlines

Deal found 27/12£422

Sun 25/109:20LHR - ORD

1 stop14h 23mJetBlue

Tue 27/109:40ORD - LHR

1 stop30h 00mJetBlue

Deal found 28/12£421

One-way flights from Heathrow to Illinois
Search for one-way flight options from Heathrow to Illinois. Find affordable one-way fares based on user searches. Data last updated 29 December 2025.

Sun 25/109:55LHR - STL

3 stops43h 38mMultiple Airlines

Deal found 28/12£346

Mon 4/519:25LHR - STL

2 stops26h 51mBritish Airways

Deal found 28/12£352

Wed 6/510:50LHR - STL

2 stops36h 31mBritish Airways

Deal found 28/12£358

Wed 6/506:30LHR - STL

1 stop12h 55mLufthansa

Deal found 28/12£363

Mon 4/512:35LHR - STL

1 stop14h 48mMultiple Airlines

Deal found 28/12£369

Tue 5/513:10LHR - STL

1 stop16h 38mBritish Airways

Deal found 28/12£372

Tue 5/516:25LHR - STL

Nonstop9h 05mFinnair

Deal found 28/12£375

Fri 16/106:00LHR - ORD

2 stops22h 42mMultiple Airlines

Deal found 26/12£382

Sat 25/406:00LHR - ORD

2 stops18h 39mAustrian Airlines

Deal found 26/12£383

Sun 18/114:50LHR - ORD

1 stop28h 45mWestJet

Deal found 26/12£385

Sun 22/207:40LHR - ORD

Nonstop9h 20mAustrian Airlines

Deal found 26/12£386

Sat 2/506:00LHR - STL

2 stops16h 26mAustrian Airlines

Deal found 28/12£386

Find flight deals from Heathrow to Illinois

Round-trip from	£413
One-way from	£346
Popular in	July
Cheapest in	February
Average price	£591
Good round-trip deal	£528 or less
Good one-way deal	£438 or less

British Airways
8/5-21/5
2 total stops
22h 30m total
London to Illinois

Search Deals

25/1
3 total stops
43h 38m total
London to Illinois

Search Deals

Highest demand for flights based on searches. 13% potential increase in price (£59 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease (£9 potential savings vs. average return price).

Search Deals

Average for round-trip flights in December 2025

Search Deals

Price to beat on a round-trip flight from London Heathrow to Illinois.

Search Deals

Price to beat on a one-way flight from London Heathrow to Illinois.

Search Deals

Cheapflights Fare Finder

Use the filters below to find and compare flights from London Heathrow Airport to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sun 10/5

08:50-14:00

1 stop11h 10m

Chicago O'Hare Intl

Mon 18/5

16:40-10:05

1 stop11h 25m

£413

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 13/4

08:50-14:00

1 stop11h 10m

Chicago O'Hare Intl

Sat 16/5

20:50-13:25

1 stop10h 35m

£415

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 19/3

09:00-17:20

1 stop13h 20m

Chicago O'Hare Intl

Sat 28/3

16:25-05:45

Nonstop8h 20m

£417

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sat 21/2

06:40-16:45

1 stop16h 05m

Chicago O'Hare Intl

Sat 28/2

19:20-18:50

2 stops17h 30m

£418

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sat 7/2

06:40-16:45

2 stops16h 05m

Chicago O'Hare Intl

Sat 14/2

19:20-18:50

2 stops17h 30m

£421

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 12/1

13:35-17:00

Nonstop9h 25m

Chicago O'Hare Intl

Sun 25/1

21:05-11:15

Nonstop8h 10m

£428

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 8/1

13:35-17:00

Nonstop9h 25m

Chicago O'Hare Intl

Wed 18/2

15:45-05:55

Nonstop8h 10m

£428

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 13/1

10:25-13:45

Nonstop9h 20m

Chicago O'Hare Intl

Tue 20/1

17:50-07:55

Nonstop8h 05m

£428

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 12/1

07:55-11:15

Nonstop9h 20m

Chicago O'Hare Intl

Mon 19/1

17:50-07:55

Nonstop8h 05m

£428

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 12/1

07:55-11:15

Nonstop9h 20m

Chicago O'Hare Intl

Wed 21/1

17:50-07:55

Nonstop8h 05m

£428

Flights are sorted by cheapest return flights first.

Deals found on 27/12

Showing 1-10 of 57 results

...

Best time to book a flight from Heathrow to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Heathrow with our price prediction graph.

Estimated return price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London Heathrow Airport to Illinois

What is the cheapest month to book a flight from London Heathrow Airport to Illinois?

Currently, February is the cheapest month in which you can book a flight from London Heathrow Airport to Illinois (average of £352). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £497). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from LHR to IL?

When flying from London Heathrow Airport to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from London Heathrow Airport to Illinois

The most flights from LHR to USIL are scheduled on a Sunday (44 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (31 on average).

How much does it cost for a return flight from London Heathrow Airport to Illinois?

Reviews of airlines servicing Illinois

Read through reviews of airlines operating flights from London Heathrow Airport to Illinois, such as Finnair, Aer Lingus, andIcelandair. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.

Finnair

7.6

Good

1,340 reviews

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

Aer Lingus

7.2

Good

1,415 reviews

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

Icelandair

7.0

Good

592 reviews

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

Lufthansa

6.8

Okay

7,659 reviews

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

British Airways

6.7

Okay

7,618 reviews

Finnair

7.6

Good

1,340 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Anonymous,May 2025

FRA - DFW

Related info for your journey

How long is the flight from London Heathrow Airport to Illinois?
Departing from London Heathrow Airport to Illinois will take you 11h 10m. The distance from London Heathrow Airport to Illinois is about 3939 mi. Both multi-stop and direct flights can be found to your destination and back.
What are the cheapest airlines to fly from London Heathrow Airport to Illinois one-way?
One-way options have recently been found by users for as low as £262 on Scandinavian Airlines. Other airlines that offer cheap prices include JetBlue from £308 and Icelandair from £326 one-way.
What are the most popular routes from London Heathrow Airport to Illinois?
The most popular flight routes from London Heathrow Airport to Illinois are London Heathrow - Chicago O'Hare Intl, London Heathrow - Chicago Midway and London Heathrow - Lambert-St Louis.
What are the most reliable airlines from London Heathrow Airport to Illinois?
Before booking your flight to Illinois from London Heathrow Airport, check out the most reliable airlines to get you to your destination on time: Austrian Airlines (88%), Brussels Airlines (88%), Lufthansa( 88%).
What are the cheapest flights from London Heathrow Airport to Illinois?
Looking at all options, your cheapest flight can be booked for £339. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £333 on average, our data indicates £1,041 when flying from London Heathrow Airport to Illinois.
Can I find deals for flights from Heathrow to Illinois that include hotel bookings?
Yes. In addition to deals on Heathrow to Illinois flights, Cheapflights offers holiday packages that include both flights and hotel.
How can I find direct flights from Heathrow to Illinois?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Heathrow to Illinois.
Can I find deals for business class flights from Heathrow to Illinois?
Yes. Cheapflights offers flight deals from Heathrow to Illinois by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from London Heathrow Airport to Illinois?
Currently, February is the cheapest month in which you can book a flight from London Heathrow Airport to Illinois (average of £352). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £497). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Direct flights to United States

Top 10 airlines flying from Heathrow to Illinois

Airline	Cheapest	Average	Flexibility	On-time
Icelandair	Cheapest£336	Average£459	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
Virgin Atlantic	Cheapest£343	Average£527	FlexibilityNo cancel fee	On-time72%	Search Virgin Atlantic flights
Scandinavian Airlines	Cheapest£353	Average£479	FlexibilityNo cancel fee	On-time77%	Search Scandinavian Airlines flights
Aer Lingus	Cheapest£363	Average£621	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
TAP AIR PORTUGAL	Cheapest£383	Average£612	FlexibilityNo cancel fee	On-timeN/A	Search TAP AIR PORTUGAL flights
Brussels Airlines	Cheapest£384	Average£539	FlexibilityNo cancel fee	On-timeN/A	Search Brussels Airlines flights
Lufthansa	Cheapest£392	Average£563	FlexibilityNo cancel fee	On-time76%	Search Lufthansa flights
British Airways	Cheapest£401	Average£564	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
Austrian Airlines	Cheapest£402	Average£609	FlexibilityNo cancel fee	On-time78%	Search Austrian Airlines flights
United Airlines	Cheapest£407	Average£669	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights

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Cheap flights from London Heathrow Airport to Illinois from £346

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 25/1. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Heathrow to Illinois

Cheapest flights from Heathrow to IllinoisExplore the most affordable flight options available from Heathrow to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 December 2025.

Explore the most affordable flight options available from Heathrow to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 December 2025.

Find flight deals from Heathrow to Illinois

Keep the following information in mind while searching for Heathrow to Illinois flight deals. Data was last updated 29 December 2025.

Round-trip from

One-way from

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Cheapflights Fare Finder

Use the filters below to find and compare flights from London Heathrow Airport to Illinois that are best for you.

Best time to book a flight from Heathrow to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Heathrow with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from London Heathrow Airport to Illinois

What is the cheapest month to book a flight from London Heathrow Airport to Illinois?

What is the cheapest time of day to fly from LHR to IL?

Find hourly flight availability from Heathrow to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 29 December 2025.

Weekly flight availability from London Heathrow Airport to Illinois

Explore weekly flight availability from Heathrow to Illinois. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 29 December 2025.

How much does it cost for a return flight from London Heathrow Airport to Illinois?

Reviews of airlines servicing Illinois

Read through reviews of airlines operating flights from London Heathrow Airport to Illinois, such as Finnair, Aer Lingus, andIcelandair. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Heathrow to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

How long is the flight from London Heathrow Airport to Illinois?

What are the cheapest airlines to fly from London Heathrow Airport to Illinois one-way?

What are the most popular routes from London Heathrow Airport to Illinois?

What are the most reliable airlines from London Heathrow Airport to Illinois?

What are the cheapest flights from London Heathrow Airport to Illinois?

Can I find deals for flights from Heathrow to Illinois that include hotel bookings?

How can I find direct flights from Heathrow to Illinois?

Can I find deals for business class flights from Heathrow to Illinois?

What is the cheapest month to book a flight from London Heathrow Airport to Illinois?

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Heathrow to Illinois

See prices for flight routes from nearby airports that may be better suited for you.

Top 10 airlines flying from Heathrow to Illinois

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Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Heathrow to Illinois?

Why should you use Cheapflights to find cheap flight tickets from Heathrow to Illinois?

Can Cheapflights find flights from Heathrow to Illinois with no change fees?

Can Cheapflights notify me if prices for flights from Heathrow to Illinois become cheaper?

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Cheapest flights from Heathrow to Illinois
Explore the most affordable flight options available from Heathrow to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 December 2025.