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Cheap flights from London Heathrow Airport to Illinois from £345

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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
27 Apr — 4 May1
1 adult
1 adult, Economy, 0 bags

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 28 March 2026.

Wed 7/1006:40
LHR
-
ORD
1 stop15h 30m
Scandinavian Airlines
Wed 14/1019:15
ORD
-
LHR
2 stops20h 20m
Scandinavian Airlines
Deal found 23/3£468
Thu 7/513:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Mon 11/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 23/3£469
Wed 6/513:05
LHR
-
ORD
1 stop14h 20m
Icelandair
Sun 17/522:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 24/3£472
Fri 17/408:00
LHR
-
ORD
1 stop14h 00m
TAP AIR PORTUGAL
Sun 26/418:00
ORD
-
LHR
1 stop12h 45m
TAP AIR PORTUGAL
Deal found 23/3£473
Wed 15/421:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Wed 6/522:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 24/3£476
Sat 9/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Fri 15/519:25
ORD
-
LHR
1 stop18h 55m
Icelandair
Deal found 24/3£477
Fri 29/513:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Sat 6/619:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 23/3£477
Fri 1/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Wed 6/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 24/3£479
Wed 15/421:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Sun 26/419:25
ORD
-
LHR
1 stop18h 55m
Icelandair
Deal found 23/3£480
Wed 6/512:25
LHR
-
MDW
1 stop12h 11m
Virgin Atlantic
Wed 13/519:13
MDW
-
LHR
1 stop11h 52m
Virgin Atlantic
Deal found 24/3£583
Mon 20/412:15
LHR
-
STL
1 stop16h 02m
Finnair
Thu 30/412:27
STL
-
LHR
1 stop19h 58m
Finnair
Deal found 23/3£592
Tue 21/412:25
LHR
-
MDW
1 stop12h 11m
Virgin Atlantic
Tue 28/419:16
MDW
-
LHR
1 stop11h 49m
Virgin Atlantic
Deal found 24/3£592

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 28 March 2026.

Round-trip from

£469

One-way from

£345

Popular in

July

Cheapest in

September

Average price

£564

Good round-trip deal

£617 or less

Good one-way deal

£492 or less
Icelandair
  • Icelandair
  • 7/5-11/5
  • 2 total stops
  • 21h 40m total
  • London to Illinois
Search Deals
5/5
  • 5/5
  • 3 total stops
  • 50h 04m total
  • London to Illinois
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£57 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 March 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

 
Customise your flight search to find flights from Heathrow to Illinois that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 28 March 2026.
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 - ORD

LHRORD

London Heathrow

Wed 23/9

07:05-21:36

2 stops20h 31m

Chicago O'Hare Intl

Wed 7/10

19:15-16:25

2 stops15h 10m

£555

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sat 2/5

06:40-16:10

2 stops15h 30m

Chicago O'Hare Intl

Sun 3/5

06:50-09:20

2 stops20h 30m

£604

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 27/5

06:40-16:10

1 stop15h 30m

Chicago O'Hare Intl

Tue 9/6

07:10-09:20

2 stops20h 10m

£607
Fastest return journey

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 16/9

11:10-13:50

Nonstop8h 40m

Chicago O'Hare Intl

Wed 23/9

21:00-10:50

Nonstop7h 50m

£616

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 20/4

19:50-21:57

2 stops32h 07m

Chicago O'Hare Intl

Mon 4/5

06:50-09:20

2 stops20h 30m

£619

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 27/4

14:10-17:20

Nonstop9h 10m

Chicago O'Hare Intl

Mon 11/5

16:25-06:45

Nonstop8h 20m

£622

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 27/4

09:55-19:52

2 stops15h 57m

Chicago O'Hare Intl

Mon 11/5

14:00-07:10

1 stop11h 10m

£626

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 3/6

17:00-16:10

1 stop29h 10m

Chicago O'Hare Intl

Sat 6/6

06:07-09:35

2 stops21h 28m

£630

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Mon 20/4

11:45-23:36

2 stops17h 51m

Lambert-St Louis

Mon 27/4

10:50-08:50

2 stops16h 00m

£635

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Thu 23/4

06:30-18:36

2 stops18h 06m

Chicago Midway

Thu 30/4

09:27-06:45

2 stops15h 18m

£640

Flights are sorted by cheapest return flights first.

Deals found on 28/3

Showing 1-10 of 60 resultsSorted by cheapest first
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6

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 £358). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £495). 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?

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 28 March 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.

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

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated 28 March 2026.
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
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
United Airlines
7.4
Good
9,504 reviews
United Airlines
7.4
Good
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
Aer Lingus
7.2
Good
1,491 reviews
United Airlines
7.4
Good
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
Icelandair
7.0
Good
627 reviews
United Airlines
7.4
Good
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
Lufthansa
6.8
Okay
7,872 reviews
United Airlines
7.4
Good
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.
British Airways
6.7
Okay
7,828 reviews
United Airlines
7.4
Good
9,504 reviews
Check prices

Comfort

7.3

Food

6.6

Entertainment

7.1

Crew

8.1

Boarding

7.7

Overall

7.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Oct 2025

YUL - ORD

Crew and customer service are 5 stars. I had a lot of luggage for a very long trip and they were nothing but helpful and found solutions to every problem. It was my first time flying with United, and they really are the friendly skies. Leg room however, on 2/3 flights was terrible. Same for entertainment: There was only a seat-mounted screen on 1/3 flights. It would have been nice to have on the longest leg of the journey.

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?

    Departing from London Heathrow Airport to Illinois will take you 8h 40m. 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 Icelandair. Other airlines that offer cheap prices include JetBlue from £313 and British Airways from £332 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: SWISS (93%), Air Canada (92%), Austrian Airlines( 92%).

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

    Looking at all options, your cheapest flight can be booked for £373. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £419 on average, our data indicates £1,222 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 £358). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £495). 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

See prices for flight routes from nearby airports that may be better suited for you.
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Luton to Miami flights

Top 10 airlines flying from Heathrow to Illinois

Discover the top 10 airlines that operate flights from Heathrow to Illinois. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 28 March 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest£348Average£550FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
IcelandairCheapest£357Average£467FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£367Average£639FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
TAP AIR PORTUGALCheapest£373Average£566FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
Scandinavian AirlinesCheapest£379Average£516FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
Brussels AirlinesCheapest£398Average£553FlexibilityNo cancel feeOn-timeN/A
Search Brussels Airlines flights
LufthansaCheapest£399Average£597FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
British AirwaysCheapest£401Average£583FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Austrian AirlinesCheapest£408Average£630FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
United AirlinesCheapest£415Average£727FlexibilityNo cancel feeOn-time69%
Search United Airlines flights

Fly with Cheapflights

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?

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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