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Cheap flights from London Heathrow Airport to Illinois from £351

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 16/6. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
21 Jun — 28 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 22 May 2026.

Thu 8/1018:45
LHR
-
ORD
1 stop27h 15m
TAP AIR PORTUGAL
Wed 14/1018:00
ORD
-
LHR
1 stop12h 45m
TAP AIR PORTUGAL
Deal found 17/5£512
Fri 9/1013:05
LHR
-
ORD
1 stop14h 20m
Icelandair
Fri 16/1022:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 18/5£513
Tue 8/913:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Wed 16/922:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 17/5£514
Sat 24/1006:40
LHR
-
ORD
1 stop15h 30m
Scandinavian Airlines
Sat 7/1119:15
ORD
-
LHR
2 stops15h 10m
Scandinavian Airlines
Deal found 18/5£520
Fri 2/1007:05
LHR
-
ORD
2 stops15h 05m
Scandinavian Airlines
Mon 5/1019:15
ORD
-
LHR
2 stops15h 10m
Scandinavian Airlines
Deal found 21/5£521
Wed 14/1007:05
LHR
-
ORD
2 stops15h 05m
Scandinavian Airlines
Wed 21/1019:15
ORD
-
LHR
2 stops15h 10m
Scandinavian Airlines
Deal found 20/5£522
Fri 28/806:40
LHR
-
ORD
1 stop15h 30m
Scandinavian Airlines
Tue 8/919:15
ORD
-
LHR
1 stop14h 45m
Scandinavian Airlines
Deal found 17/5£523
Wed 9/911:05
LHR
-
ORD
Nonstop9h 05m
Austrian Airlines
Tue 15/918:35
ORD
-
LHR
Nonstop8h 25m
Austrian Airlines
Deal found 17/5£524
Fri 2/1008:40
LHR
-
ORD
1 stop13h 15m
United Airlines
Sat 3/1015:40
ORD
-
LHR
1 stop32h 50m
United Airlines
Deal found 18/5£525
Mon 7/908:00
LHR
-
ORD
Nonstop9h 05m
Austrian Airlines
Tue 29/916:25
ORD
-
LHR
Nonstop8h 20m
Austrian Airlines
Deal found 19/5£526
Mon 22/615:15
LHR
-
MDW
1 stop13h 02m
Delta
Tue 14/719:06
MDW
-
LHR
1 stop11h 59m
Delta
Deal found 21/5£551
Mon 22/615:15
LHR
-
MDW
1 stop13h 02m
Delta
Sun 12/717:10
MDW
-
LHR
1 stop14h 05m
Delta
Deal found 21/5£573

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 22 May 2026.

Round-trip from

£512

One-way from

£351

Popular in

July

Cheapest in

February

Average price

£582

Good round-trip deal

£697 or less

Good one-way deal

£555 or less
TAP AIR PORTUGAL
  • TAP AIR PORTUGAL
  • 8/10-14/10
  • 2 total stops
  • 40h 00m total
  • London to Illinois
Search Deals
16/6
  • 16/6
  • 3 total stops
  • 31h 09m total
  • London to Illinois
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£51 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 22 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

Mon 7/9

08:00-11:05

Nonstop9h 05m

Chicago O'Hare Intl

Tue 29/9

16:25-06:45

Nonstop8h 20m

£526

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 8/9

13:05-18:15

1 stop11h 10m

Chicago O'Hare Intl

Sat 3/10

19:25-11:55

1 stop10h 30m

£589

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 27/8

07:05-16:10

2 stops15h 05m

Chicago O'Hare Intl

Sat 5/9

19:15-18:50

2 stops17h 35m

£614

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Wed 16/9

09:55-21:46

2 stops17h 51m

Chicago Midway

Wed 23/9

09:30-08:50

2 stops17h 20m

£621

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Wed 9/9

06:30-18:05

2 stops17h 35m

Chicago Midway

Wed 23/9

14:00-13:05

1 stop17h 05m

£626

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 7/10

08:00-11:10

Nonstop9h 10m

Chicago O'Hare Intl

Tue 13/10

16:25-06:45

Nonstop8h 20m

£633

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sun 6/9

08:00-11:05

Nonstop9h 05m

Chicago O'Hare Intl

Mon 28/9

16:25-06:45

Nonstop8h 20m

£646

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Thu 24/9

06:30-21:46

2 stops21h 16m

Chicago Midway

Mon 28/9

17:25-11:20

1 stop11h 55m

£655

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 15/7

13:45-12:40

1 stop28h 55m

Chicago O'Hare Intl

Sun 30/8

18:00-10:20

1 stop34h 20m

£674

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 16/6

21:25-21:25

1 stop30h 00m

Chicago O'Hare Intl

Sun 21/6

19:25-11:55

1 stop10h 30m

£680

Flights are sorted by cheapest return flights first.

Deals found on 18/5

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

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 £278). Flying from London Heathrow Airport to Illinois in June is currently the most expensive (average of £1,072). 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 22 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 22 May 2026.

The most flights from LHR to USIL are scheduled on a Thursday (52 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?

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.

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 22 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
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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
9,752 reviews
United Airlines
7.4
Good
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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
1,576 reviews
United Airlines
7.4
Good
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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
657 reviews
United Airlines
7.4
Good
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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
8,019 reviews
United Airlines
7.4
Good
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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
7,993 reviews
United Airlines
7.4
Good
9,752 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Overall

7.4

Boarding

7.7

Food

6.6

Crew

8.1

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 9h 05m. 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 £311 on JetBlue. Other airlines that offer cheap prices include Austrian Airlines from £323 and Icelandair from £325 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: SriLankan Airlines (94%), Air Canada (90%), Austrian Airlines( 90%).

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

    Looking at all options, your cheapest flight can be booked for £453. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £416 on average, our data indicates £1,199 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 £278). Flying from London Heathrow Airport to Illinois in June is currently the most expensive (average of £1,072). 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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Heathrow to Newark flights
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Gatwick to LaGuardia flights
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Stansted to Newark flights
Luton to Newark flights
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Stansted to LaGuardia flights
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Gatwick to Miami flights
Gatwick to San Francisco flights
Heathrow to Hobby flights
London City to San Francisco flights
Stansted to San Francisco flights
Stansted to Miami flights
London City to Boston flights
Gatwick to Dulles Intl flights
Stansted to Boston flights
London City to Miami flights
Heathrow to Reagan-National flights
Stansted to Dulles Intl flights
Heathrow to Ontario flights
London City to Dulles Intl flights
Heathrow to Tampa flights
Heathrow to Nashville flights
Gatwick to O'Hare Intl flights
Stansted to O'Hare Intl flights
Heathrow to George Bush Intcntl 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 22 May 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest£345Average£582FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
Aer LingusCheapest£364Average£649FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
IcelandairCheapest£369Average£501FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Scandinavian AirlinesCheapest£369Average£520FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
TAP AIR PORTUGALCheapest£385Average£514FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
Brussels AirlinesCheapest£394Average£585FlexibilityNo cancel feeOn-timeN/A
Search Brussels Airlines flights
British AirwaysCheapest£395Average£618FlexibilityNo cancel feeOn-time70%
Search British Airways flights
LufthansaCheapest£396Average£616FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
Austrian AirlinesCheapest£404Average£641FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
United AirlinesCheapest£416Average£738FlexibilityNo 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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