Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from London Heathrow Airport to Illinois from £336

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 24/4. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
29 Mar — 5 Apr1
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 27 February 2026.

Wed 15/408:00
LHR
-
ORD
1 stop14h 00m
TAP AIR PORTUGAL
Sat 25/418:05
ORD
-
LHR
1 stop12h 40m
TAP AIR PORTUGAL
Deal found 23/2£400
Thu 12/316:30
LHR
-
ORD
1 stop28h 55m
TAP AIR PORTUGAL
Sun 22/321:25
ORD
-
LHR
1 stop15h 05m
TAP AIR PORTUGAL
Deal found 23/2£401
Fri 17/419:50
LHR
-
ORD
1 stop26h 15m
TAP AIR PORTUGAL
Sat 25/418:05
ORD
-
LHR
1 stop34h 15m
TAP AIR PORTUGAL
Deal found 24/2£405
Thu 12/310:20
LHR
-
ORD
1 stop12h 25m
Scandinavian Airlines
Mon 16/320:20
ORD
-
LHR
1 stop14h 40m
Scandinavian Airlines
Deal found 25/2£406
Fri 17/418:45
LHR
-
ORD
1 stop27h 20m
TAP AIR PORTUGAL
Sun 26/418:00
ORD
-
LHR
1 stop22h 00m
TAP AIR PORTUGAL
Deal found 25/2£407
Fri 17/418:45
LHR
-
ORD
1 stop27h 20m
TAP AIR PORTUGAL
Fri 24/418:00
ORD
-
LHR
1 stop18h 50m
TAP AIR PORTUGAL
Deal found 25/2£407
Fri 17/406:40
LHR
-
ORD
1 stop15h 30m
Scandinavian Airlines
Mon 20/419:15
ORD
-
LHR
1 stop20h 25m
Scandinavian Airlines
Deal found 25/2£408
Mon 16/320:35
LHR
-
ORD
1 stop26h 45m
Icelandair
Sun 29/322:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Deal found 23/2£409
Fri 17/406:40
LHR
-
ORD
1 stop15h 30m
Scandinavian Airlines
Mon 27/419:15
ORD
-
LHR
2 stops15h 10m
Scandinavian Airlines
Deal found 25/2£410
Mon 13/407:05
LHR
-
ORD
2 stops15h 05m
Scandinavian Airlines
Mon 27/419:15
ORD
-
LHR
2 stops15h 10m
Scandinavian Airlines
Deal found 23/2£410
Thu 12/310:20
LHR
-
ORD
1 stop12h 25m
Scandinavian Airlines
Sun 22/320:20
ORD
-
LHR
2 stops17h 30m
Scandinavian Airlines
Deal found 25/2£411
Wed 16/913:25
LHR
-
MDW
1 stop14h 21m
Virgin Atlantic
Wed 23/910:35
MDW
-
LHR
1 stop14h 40m
Virgin Atlantic
Deal found 24/2£521

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 27 February 2026.

Round-trip from

£400

One-way from

£336

Popular in

July

Cheapest in

September

Average price

£435

Good round-trip deal

£514 or less

Good one-way deal

£419 or less
TAP AIR PORTUGAL
  • TAP AIR PORTUGAL
  • 15/4-25/4
  • 2 total stops
  • 26h 40m total
  • London to Illinois
Search Deals
24/4
  • 24/4
  • 3 total stops
  • 42h 34m total
  • London to Illinois
Search Deals
Highest demand for flights based on searches. 13% potential increase in price (£58 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 February 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 27 February 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

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sat 18/4

21:25-18:15

1 stop26h 50m

Chicago O'Hare Intl

Sat 25/4

19:25-11:55

1 stop10h 30m

£446

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 13/4

08:40-15:55

1 stop13h 15m

Chicago O'Hare Intl

Mon 20/4

21:30-11:45

Nonstop8h 15m

£500

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Fri 29/5

07:05-16:10

2 stops15h 05m

Chicago O'Hare Intl

Wed 26/8

19:15-16:25

2 stops15h 10m

£513

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 12/3

21:05-17:55

2 stops25h 50m

Chicago O'Hare Intl

Fri 20/3

20:20-18:30

2 stops17h 10m

£539

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Fri 17/4

14:10-17:20

Nonstop9h 10m

Chicago O'Hare Intl

Thu 23/4

16:25-06:45

Nonstop8h 20m

£556

LondonSt. Louis

LHR - STL

LHRSTL

London Heathrow

Tue 21/4

15:15-22:19

1 stop13h 04m

Lambert-St Louis

Tue 28/4

14:33-06:50

1 stop10h 17m

£559

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Tue 24/3

06:30-17:22

2 stops15h 52m

Chicago Midway

Tue 31/3

12:47-07:15

1 stop12h 28m

£574

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Tue 24/3

06:30-17:22

2 stops15h 52m

Chicago Midway

Tue 31/3

12:47-06:25

1 stop11h 38m

£574

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Sun 12/4

08:00-10:55

Nonstop8h 55m

Chicago O'Hare Intl

Thu 30/4

16:25-06:45

Nonstop8h 20m

£577

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Thu 21/5

06:40-16:10

1 stop15h 30m

Chicago O'Hare Intl

Thu 23/7

19:15-19:55

2 stops18h 40m

£585

Flights are sorted by cheapest return flights first.

Deals found on 24/2

Showing 1-10 of 60 resultsSorted by cheapest first
1
2
3
...
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 £353). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £498). 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 27 February 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 27 February 2026.

The most flights from LHR to USIL are scheduled on a Wednesday (42 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (32 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 27 February 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
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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
9,358 reviews
United Airlines
7.4
Good
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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
7.2
Good
1,464 reviews
United Airlines
7.4
Good
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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
7.1
Good
617 reviews
United Airlines
7.4
Good
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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
7,816 reviews
United Airlines
7.4
Good
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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
7,772 reviews
United Airlines
7.4
Good
9,358 reviews
Check prices

Comfort

7.3

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

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 13h 15m. 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 £308 on JetBlue. Other airlines that offer cheap prices include Icelandair from £323 and British Airways from £328 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 (91%), United Airlines (91%), Brussels Airlines( 91%).

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

    Looking at all options, your cheapest flight can be booked for £363. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £393 on average, our data indicates £1,331 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 £353). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £498). 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

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.
Heathrow to John F Kennedy Intl flights
Heathrow to Newark flights
Heathrow to LaGuardia flights
Gatwick to John F Kennedy Intl flights
London City to John F Kennedy Intl flights
Gatwick to Newark flights
Heathrow to Los Angeles flights
Heathrow to Orlando flights
Stansted to John F Kennedy Intl flights
Heathrow to Miami flights
Gatwick to LaGuardia flights
Heathrow to Boston flights
Stansted to Newark flights
Luton to John F Kennedy Intl flights
Luton to Newark flights
London City to Newark flights
Heathrow to Las Vegas flights
Heathrow to O'Hare Intl flights
Heathrow to Dallas/Fort Worth flights
Heathrow to San Francisco flights
Heathrow to Dulles Intl flights
Gatwick to Orlando flights
Gatwick to Boston flights
Heathrow to Seattle flights
Heathrow to Atlanta flights
Gatwick to Los Angeles flights
Heathrow to Hobby flights
Gatwick to Miami flights
Heathrow to Baltimore flights
Stansted to Los Angeles flights
London City to Los Angeles flights
Heathrow to Tampa flights
Stansted to Miami flights
London City to Miami flights
Stansted to Orlando flights
Heathrow to Nashville flights
Heathrow to George Bush Intcntl flights
Stansted to Boston flights
London City to Boston flights
Luton to Los Angeles flights
London City to Orlando flights
Heathrow to Ontario flights
Gatwick to Dulles Intl flights
Heathrow to Detroit flights
Heathrow to Denver flights
Gatwick to Las Vegas flights
Heathrow to Reagan-National flights
Luton to Miami flights
Heathrow to Midway flights
London City to Dulles Intl 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 27 February 2026.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest£342Average£526FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
IcelandairCheapest£345Average£460FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Aer LingusCheapest£362Average£627FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Scandinavian AirlinesCheapest£366Average£496FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
TAP AIR PORTUGALCheapest£383Average£606FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
Brussels AirlinesCheapest£383Average£538FlexibilityNo cancel feeOn-timeN/A
Search Brussels Airlines flights
LufthansaCheapest£391Average£574FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
British AirwaysCheapest£398Average£571FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Austrian AirlinesCheapest£399Average£608FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
United AirlinesCheapest£408Average£698FlexibilityNo 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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.