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Cheap flights from Illinois to London Heathrow Airport from £247

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 20/4. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LHR
10 Mar — 17 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Illinois to Heathrow

Enter your travel dates to find the best prices.

Cheapest flights from Illinois to Heathrow
Explore the most affordable flight options available from Illinois to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 8 February 2026.

Tue 7/419:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Tue 12/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 5/2£385
Sat 26/919:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Sat 10/1021:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 4/2£386
Wed 4/318:30
ORD
-
LHR
1 stop10h 20m
Icelandair
Mon 9/320:35
LHR
-
ORD
1 stop26h 45m
Icelandair
Deal found 6/2£386
Mon 2/318:30
ORD
-
LHR
1 stop10h 20m
Icelandair
Sun 8/320:35
LHR
-
ORD
1 stop26h 45m
Icelandair
Deal found 5/2£387
Sat 25/419:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Fri 8/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 6/2£388
Fri 8/519:25
ORD
-
LHR
1 stop18h 55m
Icelandair
Mon 11/513:05
LHR
-
ORD
1 stop11h 10m
Icelandair
Deal found 6/2£388
Sat 2/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Wed 13/513:05
LHR
-
ORD
1 stop14h 20m
Icelandair
Deal found 5/2£389
Sun 3/519:25
ORD
-
LHR
1 stop18h 55m
Icelandair
Sun 10/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 7/2£390
Thu 7/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Tue 12/521:25
LHR
-
ORD
1 stop30h 00m
Icelandair
Deal found 5/2£391
Sat 18/419:25
ORD
-
LHR
1 stop18h 55m
Icelandair
Sat 25/421:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 5/2£391
Sun 10/522:25
ORD
-
LHR
1 stop15h 55m
Icelandair
Fri 15/521:25
LHR
-
ORD
1 stop26h 50m
Icelandair
Deal found 7/2£393
Mon 9/306:00
MLI
-
LHR
1 stop19h 25m
Delta
Mon 16/306:30
LHR
-
MLI
2 stops21h 00m
Delta
Deal found 7/2£465

Find flight deals from Illinois to Heathrow

Keep the following information in mind while searching for Illinois to Heathrow flight deals. Data was last updated 8 February 2026.

Round-trip from

£385

One-way from

£247

Popular in

June

Cheapest in

September

Average price

£485

Good round-trip deal

£494 or less

Good one-way deal

£283 or less
Icelandair
  • Icelandair
  • 7/4-12/5
  • 2 total stops
  • 37h 20m total
  • Illinois to London
Search Deals
20/4
  • 20/4
  • 3 total stops
  • 45h 00m total
  • Illinois to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (£111 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£20 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 Illinois to London Heathrow.
Search Deals
Price to beat on a one-way flight from Illinois to London Heathrow.
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Illinois to Heathrow 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 8 February 2026.
Use the filters below to find and compare flights from Illinois to London Heathrow Airport that are best for you.

Fly from

Illinois

Fly to

Heathrow

Route

Depart

Return

Price

MolineLondon

MLI - LHR

MLILHR

Moline Quad-City

Mon 9/3

06:00-06:25

1 stop19h 25m

London Heathrow

Mon 16/3

06:30-22:30

2 stops21h 00m

£465

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 17/3

18:45-07:55

Nonstop8h 10m

London Heathrow

Tue 24/3

16:40-19:25

1 stop31h 45m

£467

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 14/4

18:40-09:00

Nonstop8h 20m

London Heathrow

Tue 21/4

07:25-14:00

1 stop12h 35m

£471

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 15/4

18:10-08:30

Nonstop8h 20m

London Heathrow

Tue 21/4

07:25-14:00

1 stop12h 35m

£471

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Mon 27/4

16:25-06:45

Nonstop8h 20m

London Heathrow

Tue 5/5

06:50-12:00

1 stop11h 10m

£471

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 29/4

21:20-11:45

Nonstop8h 25m

London Heathrow

Tue 5/5

06:50-12:00

1 stop11h 10m

£471

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 23/2

06:10-07:05

1 stop18h 55m

London Heathrow

Wed 4/3

10:00-20:43

2 stops16h 43m

£472

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Fri 10/4

19:15-18:30

2 stops17h 15m

London Heathrow

Tue 14/4

19:50-16:10

2 stops26h 20m

£480

ChicagoLondon

MDW - LHR

MDWLHR

Chicago Midway

Wed 8/4

19:20-13:05

1 stop11h 45m

London Heathrow

Wed 22/4

08:40-18:36

2 stops15h 56m

£481

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 13/4

13:02-13:15

1 stop18h 13m

London Heathrow

Tue 28/4

11:45-23:34

2 stops17h 49m

£484

Flights are sorted by cheapest return flights first.

Deals found on 6/2

Showing 1-10 of 60 results
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Best time to book a flight from Illinois to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Illinois 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 Illinois to London Heathrow Airport

What is the cheapest month to book a flight from Illinois to London Heathrow Airport?

Currently, May is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £287). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £653). 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 IL to LHR?

Find hourly flight availability from Illinois to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 8 February 2026.

When flying from Illinois to London Heathrow Airport, 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 Illinois to London Heathrow Airport

Explore weekly flight availability from Illinois to Heathrow. 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 8 February 2026.

The most flights from USIL to LHR are scheduled on a Friday (33 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (18 on average).

Related info for your journey

Find useful and relevant information for your journey from Illinois to Heathrow. 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 Illinois to London Heathrow Airport?

    For as low as £467, Delta can have you in London Heathrow Airport from Illinois in 8h 10m. The distance from Illinois to London Heathrow Airport is about 3939 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from Illinois to London Heathrow Airport one-way?

    The cheapest airline one-way is TAP AIR PORTUGAL, with whom users have recently found tickets for as low as £162. However, be on the lookout for offers from Lufthansa and British Airways, as they are both options that can get you from Illinois to London Heathrow Airport for a low price.

  • What are the most popular routes from Illinois to London Heathrow Airport?

    The most popular route from Illinois to London Heathrow Airport is Chicago O'Hare Intl - London Heathrow. You may also consider Chicago Midway - London Heathrow or Lambert-St Louis - London Heathrow.

  • What are the most reliable airlines from Illinois to London Heathrow Airport?

    No one likes to see their flight delayed. When booking a flight from Illinois to London Heathrow Airport consider choosing Aer Lingus (72%), American Airlines (67%) or Alaska Airlines (67%) as they are the most reliable in getting you off to your destination on time.

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

    On average you can expect to pay £421 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £148 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £356.

  • Can I find deals for flights from Illinois to Heathrow that include hotel bookings?

    Yes. In addition to deals on Illinois to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Heathrow.

  • Can I find deals for business class flights from Illinois to Heathrow?

    Yes. Cheapflights offers flight deals from Illinois to Heathrow 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 Illinois to London Heathrow Airport?

    Currently, May is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £287). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £653). 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

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Luton
Northampton
Wembley
Gatwick
Slough
Ilford
Hounslow
Brentford
Hayes
Colchester
Watford
Guildford
Swindon
Bedford
Chelmsford
Eastbourne
Crawley
Kingston upon Thames

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Alternative routes for Illinois to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
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Boston to London City flights
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Boston to Stansted flights
Newark to Luton flights
Newark to London City flights
Baltimore to Gatwick flights
Los Angeles to Gatwick flights
Philadelphia to Heathrow flights
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O'Hare Intl to Gatwick flights
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Minneapolis to Heathrow flights
Los Angeles to Stansted flights
San Francisco to Gatwick flights
Detroit to Heathrow flights
Orlando to Gatwick flights
O'Hare Intl to Stansted flights
Tampa to Heathrow flights
O'Hare Intl to London City flights
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Los Angeles to London City flights

Top 7 airlines flying from Illinois to Heathrow

Discover the top 7 airlines that operate flights from Illinois to Heathrow. 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 8 February 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£353Average£508FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
American AirlinesCheapest£380Average£604FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
FinnairCheapest£408Average£568FlexibilityNo cancel feeOn-time76%
Search Finnair flights
British AirwaysCheapest£417Average£563FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Aer LingusCheapest£443Average£571FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£456Average£655FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
IberiaCheapest£465Average£527FlexibilityNo cancel feeOn-time77%
Search Iberia 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 Illinois to Heathrow?

When you search for this flight from Illinois to Heathrow, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

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

By finding flights from multiple airlines and providers at completely no cost, Cheapflights helps millions of users like you annually find the best flights to Heathrow from Illinois.

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

Cheapflights does show flights with no change fees to all users. To see these options for flights from Illinois to Heathrow, users can toggle the no change fees filter when performing a flight search.

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

Yes, Cheapflights offers price alerts on Illinois to Heathrow flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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