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Cheap flights from Illinois to London Heathrow Airport from £170

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 12/10. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LHR
15 Oct — 22 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Illinois to Heathrow

Keep the following information in mind while searching for Illinois to Heathrow flight deals. Data was last updated 15 September 2025.

Round-trip from

£372

One-way from

£170

Popular in

June

Cheapest in

February

Average price

£486

Good round-trip deal

£441 or less

Good one-way deal

£275 or less
United Airlines
  • United Airlines
  • 27/10-3/11
  • 2 total stops
  • 44h 20m total
  • Illinois to London
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WestJet
  • WestJet
  • 12/10
  • 1 total stop
  • 36h 35m total
  • Illinois to London
Search Deals
Highest demand for flights based on searches. 21% potential increase in price (£113 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£20 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Illinois to London Heathrow.
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Price to beat on a one-way flight from Illinois to London Heathrow.
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Find flight deals from Illinois to Heathrow

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 15 September 2025.

Sun 19/1010:40ORD - LHR
1 stop13h 50mAir Canada
Tue 4/1109:00LHR - ORD
2 stops15h 39mAir Canada
Deal found 13/9£372
Tue 28/1018:23MDW - LHR
1 stop9h 22mVirgin Atlantic
Tue 4/1111:05LHR - MDW
1 stop12h 38mVirgin Atlantic
Deal found 13/9£372
Sun 21/919:25ORD - LHR
1 stop10h 30mIcelandair
Tue 30/921:25LHR - ORD
1 stop29h 50mIcelandair
Deal found 13/9£373
Wed 24/921:50ORD - LHR
Nonstop7h 55mUnited Airlines
Tue 21/1006:50LHR - ORD
1 stop11h 15mUnited Airlines
Deal found 13/9£374
Sun 21/918:00ORD - LHR
Nonstop8h 20mAir Canada
Tue 30/908:30LHR - ORD
Nonstop9h 00mAir Canada
Deal found 14/9£375
Sat 1/1120:18ORD - LHR
1 stop32h 22mUnited Airlines
Wed 26/1113:25LHR - ORD
1 stop24h 35mUnited Airlines
Deal found 14/9£376
Mon 22/919:05ORD - LHR
1 stop11h 55mSWISS
Tue 21/1008:45LHR - ORD
1 stop13h 10mSWISS
Deal found 14/9£377
Mon 27/1022:45ORD - LHR
Nonstop7h 50mBritish Airways
Tue 11/1115:45LHR - ORD
Nonstop9h 00mBritish Airways
Deal found 14/9£377
Tue 28/1015:35ORD - LHR
2 stops14h 45mMultiple Airlines
Thu 6/1106:50LHR - ORD
2 stops14h 05mMultiple Airlines
Deal found 14/9£378
Mon 6/1013:26ORD - LHR
1 stop11h 49mDelta
Wed 15/1006:15LHR - ORD
1 stop14h 45mDelta
Deal found 14/9£379
Sun 28/920:10ORD - LHR
1 stop11h 00mDelta
Tue 21/1006:30LHR - ORD
1 stop13h 40mDelta
Deal found 14/9£380
Tue 18/1110:30ORD - LHR
2 stops23h 30mScandinavian Airlines
Sun 23/1106:40LHR - ORD
2 stops16h 05mScandinavian Airlines
Deal found 13/9£380

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 15 September 2025.
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

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Mon 1/12

21:05-11:15

Nonstop8h 10m

London Heathrow

Tue 9/12

06:50-12:10

1 stop11h 20m

£373

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 22/10

14:08-06:30

1 stop10h 22m

London Heathrow

Mon 27/10

16:40-15:10

1 stop27h 30m

£377

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 14/10

18:20-11:00

1 stop10h 40m

London Heathrow

Wed 29/10

06:20-16:10

1 stop14h 50m

£379

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 30/9

14:05-06:45

1 stop10h 40m

London Heathrow

Fri 17/10

06:30-14:10

1 stop13h 40m

£380

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Sun 28/9

21:25-11:45

Nonstop8h 20m

London Heathrow

Wed 15/10

08:30-11:30

Nonstop9h 00m

£381

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 21/10

10:40-06:30

1 stop13h 50m

London Heathrow

Tue 28/10

13:25-11:18

1 stop26h 53m

£381

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 10/12

12:50-07:10

1 stop12h 20m

London Heathrow

Fri 19/12

13:35-17:00

Nonstop9h 25m

£381

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Fri 3/10

19:25-11:55

1 stop10h 30m

London Heathrow

Thu 16/10

13:05-18:15

1 stop11h 10m

£385

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Thu 15/1

18:30-10:50

1 stop10h 20m

London Heathrow

Sat 24/1

12:15-17:20

1 stop11h 05m

£385

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Mon 6/10

19:25-11:55

1 stop10h 30m

London Heathrow

Sun 9/11

12:15-17:20

1 stop11h 05m

£385

Flights are sorted by cheapest return flights first.

Deals found on 12/9

Showing 1-10 of 55 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, January is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £112). Flying from Illinois to London Heathrow Airport in August is currently the most expensive (average of £164). 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 15 September 2025.

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 15 September 2025.

The most flights from USIL to LHR are scheduled on a Friday (57 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (43 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 £373, United Airlines 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 JetBlue, with whom users have recently found tickets for as low as £239. However, be on the lookout for offers from Delta and KLM, 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 (64%), American Airlines (62%) or Air Canada (62%) 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 £403 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £256 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £300.

  • 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, January is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £112). Flying from Illinois to London Heathrow Airport in August is currently the most expensive (average of £164). 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
Hounslow
Gatwick
Slough
Northampton
Luton
Deal
Wembley
Ilford
Crawley
Hayes
Watford
Folkestone
Winchester
Chichester
Ipswich
Swindon
Dartford
Eastbourne

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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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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 15 September 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£355Average£544FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
American AirlinesCheapest£382Average£622FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
FinnairCheapest£410Average£644FlexibilityNo cancel feeOn-time76%
Search Finnair flights
IberiaCheapest£442Average£534FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Aer LingusCheapest£445Average£574FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
British AirwaysCheapest£455Average£608FlexibilityNo cancel feeOn-time70%
Search British Airways flights
United AirlinesCheapest£457Average£689FlexibilityNo 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 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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