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Cheap flights from London Heathrow Airport to Illinois from £397

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 21/9. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
10 Jun — 17 Jun1
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 11 May 2026.

Wed 16/913:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Fri 9/1022:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 7/5£505
Wed 14/1013:25
LHR
-
MDW
1 stop14h 20m
Delta
Tue 20/1017:25
MDW
-
LHR
1 stop13h 50m
Delta
Deal found 11/5£505
Fri 2/1008:00
LHR
-
ORD
1 stop14h 00m
TAP AIR PORTUGAL
Sun 4/1018:00
ORD
-
LHR
1 stop12h 45m
TAP AIR PORTUGAL
Deal found 7/5£506
Thu 24/919:50
LHR
-
ORD
1 stop26h 10m
TAP AIR PORTUGAL
Sun 27/918:00
ORD
-
LHR
1 stop18h 50m
TAP AIR PORTUGAL
Deal found 8/5£507
Sat 12/908:00
LHR
-
ORD
Nonstop9h 10m
United Airlines
Sat 12/920:40
ORD
-
LHR
1 stop29h 55m
United Airlines
Deal found 8/5£508
Sat 21/1110:25
LHR
-
ORD
Nonstop9h 20m
United Airlines
Sat 21/1118:30
ORD
-
LHR
1 stop30h 00m
United Airlines
Deal found 9/5£508
Tue 29/913:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Tue 6/1019:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 10/5£510
Sat 17/1013:10
LHR
-
ORD
Nonstop8h 45m
British Airways
Thu 22/1021:15
ORD
-
LHR
Nonstop8h 00m
British Airways
Deal found 11/5£511
Thu 15/1011:10
LHR
-
ORD
Nonstop8h 40m
British Airways
Thu 22/1017:00
ORD
-
LHR
Nonstop7h 50m
British Airways
Deal found 11/5£511
Tue 7/708:15
LHR
-
ORD
1 stop15h 05m
JetBlue
Wed 15/710:56
ORD
-
LHR
1 stop13h 34m
JetBlue
Deal found 11/5£512
Tue 22/913:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Tue 29/919:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 11/5£513
Tue 1/913:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Tue 8/919:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Deal found 10/5£515

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 11 May 2026.

Round-trip from

£505

One-way from

£388

Popular in

July

Cheapest in

February

Average price

£568

Good round-trip deal

£680 or less

Good one-way deal

£528 or less
Icelandair
  • Icelandair
  • 16/9-9/10
  • 2 total stops
  • 27h 05m total
  • London to Illinois
Search Deals
28/5
  • 28/5
  • 3 total stops
  • 40h 40m total
  • London to Illinois
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£49 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 May 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 11 May 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 9/9

07:30-17:50

1 stop16h 20m

Chicago O'Hare Intl

Wed 23/9

17:00-06:50

Nonstop7h 50m

£597

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 1/9

10:20-17:50

1 stop13h 30m

Chicago O'Hare Intl

Tue 8/9

18:15-08:05

Nonstop7h 50m

£599

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 5/11

06:00-12:40

1 stop12h 40m

Chicago O'Hare Intl

Tue 10/11

18:50-13:00

1 stop12h 10m

£619

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Wed 9/9

06:30-18:05

2 stops17h 35m

Chicago Midway

Wed 23/9

13:05-11:20

1 stop16h 15m

£624

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Tue 22/9

13:25-21:46

1 stop14h 21m

Chicago Midway

Tue 29/9

13:00-07:10

1 stop12h 10m

£638
Fastest return journey

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sun 1/11

07:40-10:45

Nonstop9h 05m

Chicago O'Hare Intl

Wed 11/11

15:45-05:55

Nonstop8h 10m

£647

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 15/9

08:00-11:10

Nonstop9h 10m

Chicago O'Hare Intl

Sun 27/9

16:25-06:45

Nonstop8h 20m

£649

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Wed 23/9

09:55-20:31

2 stops16h 36m

Lambert-St Louis

Tue 29/9

10:45-06:45

2 stops14h 00m

£652

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 3/6

07:05-16:10

2 stops15h 05m

Chicago O'Hare Intl

Thu 11/6

10:05-09:35

2 stops17h 30m

£652

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 16/9

08:40-14:30

1 stop11h 50m

Chicago O'Hare Intl

Fri 2/10

16:20-10:45

1 stop12h 25m

£666

Flights are sorted by cheapest return flights first.

Deals found on 8/5

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

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 43 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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 £275). Flying from London Heathrow Airport to Illinois in December is currently the most expensive (average of £890). 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 11 May 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 11 May 2026.

The most flights from LHR to USIL are scheduled on a Monday (52 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (52 on average).

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 11 May 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
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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
9,700 reviews
United Airlines
7.4
Good
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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
7.3
Good
1,551 reviews
United Airlines
7.4
Good
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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
653 reviews
United Airlines
7.4
Good
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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
7,992 reviews
United Airlines
7.4
Good
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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
7,972 reviews
United Airlines
7.4
Good
9,700 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

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 12h 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 £307 on JetBlue. Other airlines that offer cheap prices include Austrian Airlines from £318 and Icelandair from £321 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: United Airlines (86%), Air Canada (86%), Brussels Airlines( 86%).

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

    Looking at all options, your cheapest flight can be booked for £405. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £431 on average, our data indicates £1,010 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 £275). Flying from London Heathrow Airport to Illinois in December is currently the most expensive (average of £890). 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.
Heathrow to John F Kennedy Intl flights
Heathrow to Newark flights
Gatwick to John F Kennedy Intl flights
Heathrow to LaGuardia flights
Stansted to John F Kennedy Intl flights
Gatwick to Newark flights
London City to John F Kennedy Intl flights
Gatwick to LaGuardia flights
Heathrow to Orlando flights
Heathrow to Los Angeles flights
Luton to John F Kennedy Intl flights
Heathrow to Boston flights
Heathrow to San Francisco flights
London City to Newark flights
Luton to Newark flights
Stansted to Newark flights
Heathrow to Miami flights
Heathrow to O'Hare Intl flights
Heathrow to Dulles Intl flights
Gatwick to Boston flights
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Gatwick to Orlando flights
Heathrow to Hobby flights
Gatwick to Los Angeles flights
Stansted to Los Angeles flights
London City to Los Angeles flights
Stansted to Orlando flights
Gatwick to Miami flights
London City to Boston flights
Heathrow to George Bush Intcntl flights
Stansted to Boston flights
Heathrow to Atlanta flights
Stansted to Miami flights
Gatwick to San Francisco flights
London City to Miami flights
London City to San Francisco flights
Stansted to LaGuardia flights
Heathrow to Tampa flights
Gatwick to O'Hare Intl flights
Gatwick to Dulles Intl flights
Heathrow to Reagan-National flights
Heathrow to Midway flights
Stansted to Dulles Intl flights
London City to O'Hare Intl flights
Stansted to O'Hare Intl flights
London City to Orlando flights
Stansted to San Francisco 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 11 May 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest£340Average£574FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
Aer LingusCheapest£359Average£632FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
IcelandairCheapest£362Average£490FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Scandinavian AirlinesCheapest£364Average£513FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
TAP AIR PORTUGALCheapest£380Average£507FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
British AirwaysCheapest£389Average£603FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Brussels AirlinesCheapest£389Average£577FlexibilityNo cancel feeOn-timeN/A
Search Brussels Airlines flights
LufthansaCheapest£390Average£603FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
Austrian AirlinesCheapest£395Average£634FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
United AirlinesCheapest£410Average£725FlexibilityNo 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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