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

Departing from London Heathrow Airport to Illinois will take you 12h 25m. 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 £306 on JetBlue. Other airlines that offer cheap prices include Aer Lingus from £314 and Austrian Airlines from £317 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 £404. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £193 on average, our data indicates £2,951 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: Air Canada (88%), Austrian Airlines (88%), United Airlines( 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 Icelandair 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.

£265+ Cheap Flights from London Heathrow Airport to Illinois

Cheap flight deals from Heathrow to Illinois

Enter your travel dates to find the best prices.

Cheapest

Best

Direct

Last-minute

One-way

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 24 August 2026.

Wed 16/912:10 -

1 stop30h 25m

Fri 18/910:50 -

1 stop14h 05m

Deal found 21/8£467

Tue 8/912:10 -

1 stop33h 45m

Thu 10/914:30 -

1 stop10h 25m

Deal found 22/8£468

Thu 17/916:35 -

1 stop29h 25m

Sat 26/918:05 -

1 stop12h 40m

Deal found 21/8£470

Wed 16/908:00 -

1 stop14h 00m

Sun 18/1018:00 -

1 stop12h 45m

Deal found 23/8£470

Tue 27/1007:05 -

2 stops15h 40m

Tue 3/1119:15 -

3 stops19h 35m

Deal found 19/8£471

Thu 17/916:35 -

1 stop29h 25m

Sun 27/918:00 -

1 stop12h 45m

Deal found 19/8£473

Thu 1/1019:50 -

1 stop26h 10m

Sun 11/1018:00 -

1 stop34h 20m

Deal found 19/8£473

Thu 17/916:35 -

1 stop29h 25m

Sun 11/1018:00 -

1 stop34h 20m

Deal found 19/8£475

Sat 10/1017:30 -

2 stops28h 40m

Sat 17/1019:15 -

2 stops18h 40m

Deal found 20/8£477

Mon 7/1212:40 -

1 stop16h 16m

Tue 29/1211:20 -

1 stop13h 45m

Deal found 19/8£512

Thu 10/1212:40 -

1 stop16h 16m

Tue 29/1217:25 -

1 stop12h 15m

Deal found 19/8£534

Thu 17/914:05 -

2 stops30h 30m

Wed 23/911:45 -

2 stops14h 50m

Deal found 21/8£577

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 24 August 2026.

Fri 2/1016:15 -

1 stop18h 46m

Sun 4/1005:00 -

1 stop10h 20m

Deal found 23/8£517

Tue 15/1210:20 -

1 stop12h 25m

Wed 30/1219:15 -

2 stops20h 20m

Deal found 20/8£539

Tue 3/1112:15 -

1 stop11h 05m

Sat 28/1118:30 -

1 stop10h 20m

Deal found 21/8£593

Mon 21/908:00 -

Nonstop9h 10m

Mon 5/1016:25 -

Nonstop8h 20m

Deal found 23/8£627

Wed 7/1006:30 -

2 stops17h 30m

Wed 21/1017:31 -

1 stop13h 34m

Deal found 19/8£629

Wed 16/911:45 -

2 stops16h 59m

Tue 29/910:48 -

2 stops14h 22m

Deal found 19/8£630

Wed 23/906:30 -

1 stop12h 55m

Fri 2/1015:30 -

1 stop19h 10m

Deal found 24/8£632

Thu 8/1014:05 -

2 stops14h 54m

Mon 12/1012:10 -

2 stops12h 20m

Deal found 23/8£693

Wed 16/916:25 -

Nonstop9h 05m

Wed 23/921:35 -

Nonstop8h 00m

Deal found 23/8£732

Wed 7/1012:15 -

1 stop18h 03m

Wed 14/1006:49 -

2 stops17h 26m

Deal found 22/8£816

Thu 22/1006:40 -

1 stop15h 30m

Sun 25/1020:15 -

1 stop16h 25m

Deal found 23/8£566

Sun 20/918:40 -

1 stop27h 30m

Fri 25/919:15 -

1 stop12h 20m

Deal found 19/8£566

Wed 7/1006:30 -

2 stops17h 30m

Wed 14/1010:59 -

1 stop14h 16m

Deal found 20/8£632

Tue 22/906:15 -

2 stops18h 18m

Tue 29/909:29 -

2 stops14h 56m

Deal found 23/8£640

Wed 7/1009:30 -

1 stop15h 11m

Wed 14/1009:30 -

1 stop14h 25m

Deal found 22/8£657

Tue 13/1013:05 -

1 stop11h 10m

Sun 22/1118:30 -

1 stop10h 20m

Deal found 20/8£662

Fri 18/921:05 -

2 stops25h 05m

Mon 21/919:15 -

1 stop14h 45m

Deal found 22/8£576

Tue 1/1208:40 -

2 stops15h 21m

Wed 9/1213:02 -

1 stop12h 48m

Deal found 23/8£635

Mon 21/915:15 -

1 stop13h 29m

Mon 5/1013:00 -

1 stop11h 25m

Deal found 20/8£646

Thu 8/1006:50 -

2 stops14h 53m

Thu 15/1010:27 -

2 stops14h 28m

Deal found 23/8£665

Fri 11/1207:05 -

2 stops15h 40m

Wed 30/1219:15 -

2 stops17h 35m

Deal found 22/8£593

Wed 28/1008:40 -

2 stops17h 11m

Tue 3/1112:00 -

2 stops13h 45m

Deal found 19/8£657

Thu 17/906:30 -

2 stops18h 03m

Tue 29/914:00 -

1 stop17h 05m

Deal found 19/8£659

Tue 6/1011:10 -

1 stop19h 01m

Tue 13/1011:33 -

1 stop17h 22m

Deal found 22/8£811

Thu 8/1015:30 -

1 stop27h 55m

Mon 12/1012:20 -

1 stop12h 55m

Deal found 19/8£673

Wed 2/1207:35 -

2 stops18h 46m

Sun 6/1218:59 -

1 stop29h 56m

Deal found 19/8£816

Thu 17/1206:40 -

1 stop16h 05m

Mon 28/1219:15 -

2 stops15h 10m

Deal found 19/8£603

Thu 5/1108:40 -

2 stops15h 20m

Thu 26/1116:19 -

1 stop13h 21m

Deal found 21/8£664

Sun 4/1014:25 -

1 stop15h 17m

Sun 11/1010:48 -

1 stop18h 27m

Deal found 20/8£891

Sun 15/1111:10 -

2 stops16h 25m

Sat 21/1109:40 -

2 stops15h 00m

Deal found 24/8£694

Find flight deals from Heathrow to Illinois

Round-trip from	£467
One-way from	£265
Popular in	August
Cheapest in	February
Average price	£717
Good round-trip deal	£599 or less
Good one-way deal	£511 or less

United Airlines
16/9-18/9
2 total stops
44h 30m total
London to Illinois

Search Deals

23/9
3 total stops
57h 20m total
London to Illinois

Search Deals

Highest demand for flights based on searches. 9% potential increase in price (£46 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease (£10 potential savings vs. average return price).

Search Deals

Average for round-trip flights in August 2026

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

Cheapest return flight

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Fri 2/10

16:15-05:01

1 stop18h 46m

Chicago O'Hare Intl

Sun 4/10

05:00-21:20

1 stop10h 20m

£517

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Tue 15/12

10:20-16:45

1 stop12h 25m

Chicago O'Hare Intl

Wed 30/12

19:15-21:35

2 stops20h 20m

£539

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Thu 22/10

06:40-16:10

1 stop15h 30m

Chicago O'Hare Intl

Sun 25/10

20:15-17:40

1 stop16h 25m

£566

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Sun 20/9

18:40-16:10

1 stop27h 30m

Chicago O'Hare Intl

Fri 25/9

19:15-13:35

1 stop12h 20m

£566

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Fri 18/9

21:05-16:10

2 stops25h 05m

Chicago O'Hare Intl

Mon 21/9

19:15-16:00

1 stop14h 45m

£576

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Tue 3/11

12:15-17:20

1 stop11h 05m

Chicago O'Hare Intl

Sat 28/11

18:30-10:50

1 stop10h 20m

£593

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Fri 11/12

07:05-16:45

2 stops15h 40m

Chicago O'Hare Intl

Wed 30/12

19:15-18:50

2 stops17h 35m

£593

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Thu 17/12

06:40-16:45

1 stop16h 05m

Chicago O'Hare Intl

Mon 28/12

19:15-16:25

2 stops15h 10m

£603

LondonChicago

LHR London Heathrow - ORD Chicago O'Hare Intl

LHRORD

London Heathrow

Mon 21/9

08:00-11:10

Nonstop9h 10m

Chicago O'Hare Intl

Mon 5/10

16:25-06:45

Nonstop8h 20m

£627

LondonChicago

LHR London Heathrow - MDW Chicago Midway

LHRMDW

London Heathrow

Wed 7/10

06:30-18:00

2 stops17h 30m

Chicago Midway

Wed 21/10

17:31-13:05

1 stop13h 34m

£629

Flights are sorted by cheapest return flights first.

Deals found on 20/8

Showing 1-10 of 60 resultsSorted by cheapest first

...

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.

LHR-ORD

LHR-MDW

LHR-STL

LHR-MWA

LHR-MLI

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

LHR-USIL

LHR-ORD

LHR-MDW

LHR-STL

LHR-MWA

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 £464). Flying from London Heathrow Airport to Illinois in August is currently the most expensive (average of £787). 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 Friday (49 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (47 on average).

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 £550 and £800 in September.
The cheapest return price found within the last 5 days was £467 on United Airlines (16 Sept–18 Sept).

How far ahead should I book a flight from London Heathrow Airport to Illinois?

The price you pay for your flight from London Heathrow Airport to Illinois may vary depending on when you book. For the best chance of a lower fare, look to book 79 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

Reviews of airlines servicing Illinois

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

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

Had to go through TSA again, already purchased bottle drink. TSA would not let through, United changed gates last minute. This experience bad for everyone. Staff rude, not our fault. Staff from Chicago to Wichita excellent!

United Airlines

7.4

Good

10,115 reviews

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

Aer Lingus

7.3

Good

1,722 reviews

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

Icelandair

6.9

Okay

735 reviews

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

Lufthansa

6.8

Okay

8,214 reviews

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

British Airways

6.7

Okay

8,187 reviews

United Airlines

7.4

Good

10,115 reviews

Check prices

Reviews

1 / 20

4.0

Okay

Chris,Aug 2026

MIA - ORD

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 12h 25m. 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 £306 on JetBlue. Other airlines that offer cheap prices include Aer Lingus from £314 and Austrian Airlines from £317 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: Air Canada (88%), Austrian Airlines (88%), United Airlines( 88%).
What are the cheapest flights from London Heathrow Airport to Illinois?
Looking at all options, your cheapest flight can be booked for £404. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £193 on average, our data indicates £2,951 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 £464). Flying from London Heathrow Airport to Illinois in August is currently the most expensive (average of £787). 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

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Alternative routes for Heathrow to Illinois

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Luton to Los Angeles flights

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Stansted to Dulles Intl flights

Heathrow to Denver flights

Stansted to Boston flights

London City to Dulles Intl flights

Top 10 airlines flying from Heathrow to Illinois

Airline	Cheapest	Average	Flexibility	On-time
Virgin Atlantic	Cheapest£297	Average£616	FlexibilityNo cancel fee	On-time72%	Search Virgin Atlantic flights
Icelandair	Cheapest£361	Average£494	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
Scandinavian Airlines	Cheapest£370	Average£533	FlexibilityNo cancel fee	On-time77%	Search Scandinavian Airlines flights
JetBlue	Cheapest£377	Average£672	FlexibilityNo cancel fee	On-time62%	Search JetBlue flights
TAP AIR PORTUGAL	Cheapest£381	Average£566	FlexibilityNo cancel fee	On-timeN/A	Search TAP AIR PORTUGAL flights
Brussels Airlines	Cheapest£388	Average£632	FlexibilityNo cancel fee	On-timeN/A	Search Brussels Airlines flights
Lufthansa	Cheapest£398	Average£650	FlexibilityNo cancel fee	On-time76%	Search Lufthansa flights
British Airways	Cheapest£399	Average£672	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
Aer Lingus	Cheapest£413	Average£679	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
United Airlines	Cheapest£417	Average£734	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights

Fly with Cheapflights

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

Cheapflights helps you search for flights from Heathrow to Illinois via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Heathrow to Illinois for you. Better yet — we are completely free to use.

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

Yes! Cheapflights helps users easily find flights from Heathrow to Illinois with no change fees.

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

Of course! You can now track prices for flights from Heathrow to Illinois and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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Cheap flights from London Heathrow Airport to Illinois from £265

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 23/9. 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 24 August 2026.

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 24 August 2026.

Best flights from Heathrow to IllinoisDiscover 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 24 August 2026.

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 24 August 2026.

Direct flights from Heathrow to IllinoisExplore direct flight options from Heathrow to Illinois based on user searches, and compare prices and availability for your desired travel dates. Data last updated 24 August 2026.

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 24 August 2026.

Last-minute flights from Heathrow to IllinoisDiscover last-minute flight deals from Heathrow to Illinois. Data last updated 24 August 2026 and is based on user searches.

Discover last-minute flight deals from Heathrow to Illinois. Data last updated 24 August 2026 and is based on user searches.

One-way flights from Heathrow to IllinoisSearch for one-way flight options from Heathrow to Illinois. Find affordable one-way fares based on user searches. Data last updated 24 August 2026.

Search for one-way flight options from Heathrow to Illinois. Find affordable one-way fares based on user searches. Data last updated 24 August 2026.

Find flight deals from Heathrow to Illinois

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

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

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 24 August 2026.

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

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 24 August 2026.

The most flights from LHR to USIL are scheduled on a Friday (49 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (47 on average).

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 £550 and £800 in September.The cheapest return price found within the last 5 days was £467 on United Airlines (16 Sept–18 Sept).

How far ahead should I book a flight from London Heathrow Airport to Illinois?

The price you pay for your flight from London Heathrow Airport to Illinois may vary depending on when you book. For the best chance of a lower fare, look to book 79 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

Reviews of airlines servicing Illinois

Read through reviews of airlines operating flights from London Heathrow Airport to Illinois, such as United Airlines,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

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

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Heathrow to Illinois

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

Complete your trip

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Heathrow and Illinois flights

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Heathrow to Illinois flights

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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 24 August 2026.

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 24 August 2026.

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 24 August 2026.

Last-minute flights from Heathrow to Illinois
Discover last-minute flight deals from Heathrow to Illinois. Data last updated 24 August 2026 and is based on user searches.

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 24 August 2026.

London Heathrow Airport to Illinois flights typically cost between £550 and £800 in September.
The cheapest return price found within the last 5 days was £467 on United Airlines (16 Sept–18 Sept).