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Cheap flights from Illinois to London 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 9/11. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LON
12 Oct — 19 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Illinois to London

Keep the following information in mind while searching for Illinois to London flight deals. Data was last updated 12 September 2025.

Round-trip from

£373

One-way from

£170

Popular in

June

Cheapest in

February

Average price

£489

Good round-trip deal

£361 or less

Good one-way deal

£276 or less
19/10-4/11
  • 19/10-4/11
  • 3 total stops
  • 29h 29m total
  • Illinois to London
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25/9
  • 25/9
  • 2 total stops
  • 19h 10m 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).
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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 (LON).
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Price to beat on a one-way flight from Illinois to London (LON).
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Find flight deals from Illinois to London

Cheapest flights from Illinois to London
Explore the most affordable flight options available from Illinois to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 12 September 2025.

Sun 19/1010:40ORD - LHR
1 stop13h 50mMultiple Airlines
Tue 4/1109:00LHR - ORD
2 stops15h 39mMultiple Airlines
Deal found 10/9£373
Mon 27/1019:50ORD - LGW
1 stop17h 00mSWISS
Mon 3/1118:40LGW - ORD
1 stop27h 40mSWISS
Deal found 11/9£373
Mon 10/1118:30ORD - LTN
1 stop13h 30mMultiple Airlines
Sun 23/1106:00LTN - ORD
1 stop17h 20mMultiple Airlines
Deal found 10/9£374
Wed 24/921:50ORD - LHR
Nonstop7h 55mUnited Airlines
Tue 14/1006:50LHR - ORD
1 stop11h 15mUnited Airlines
Deal found 10/9£374
Tue 30/921:25ORD - LHR
Nonstop8h 20mUnited Airlines
Tue 7/1006:50LHR - ORD
1 stop11h 15mUnited Airlines
Deal found 11/9£374
Tue 14/1015:50ORD - LHR
1 stop10h 45mMultiple Airlines
Mon 20/1019:30LHR - ORD
1 stop23h 50mMultiple Airlines
Deal found 10/9£375
Wed 3/1206:40ORD - LGW
1 stop17h 20mMultiple Airlines
Tue 9/1213:00LGW - ORD
1 stop29h 45mMultiple Airlines
Deal found 10/9£375
Fri 24/1019:25ORD - STN
2 stops18h 25mMultiple Airlines
Sun 2/1108:30STN - ORD
2 stops14h 50mMultiple Airlines
Deal found 12/9£375
Wed 3/1218:30ORD - LTN
1 stop12h 25mMultiple Airlines
Thu 11/1206:00LTN - ORD
1 stop17h 20mMultiple Airlines
Deal found 10/9£376
Thu 18/921:31ORD - LHR
1 stop27h 24mUnited Airlines
Sun 21/906:50LHR - ORD
1 stop11h 15mUnited Airlines
Deal found 10/9£376
Tue 30/911:13ORD - LGW
1 stop13h 07mMultiple Airlines
Sat 15/1106:05LGW - ORD
2 stops38h 55mMultiple Airlines
Deal found 11/9£376
Sun 16/1118:30ORD - LTN
1 stop14h 20mMultiple Airlines
Sun 23/1106:00LTN - ORD
1 stop17h 20mMultiple Airlines
Deal found 11/9£377

Cheapflights Fare Finder

 
Customise your flight search to find flights from Illinois to London 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 12 September 2025.
Use the filters below to find and compare flights from Illinois to London that are best for you.

Fly from

Illinois

Fly to

London

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

£374

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 12/11

17:50-07:55

Nonstop8h 05m

London Heathrow

Wed 19/11

06:50-12:10

1 stop11h 20m

£374

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Sun 28/9

16:00-06:20

Nonstop8h 20m

London Heathrow

Tue 7/10

06:50-12:05

1 stop11h 15m

£374

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Mon 29/9

16:00-06:20

Nonstop8h 20m

London Heathrow

Tue 7/10

06:50-12:05

1 stop11h 15m

£374

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Wed 3/12

18:30-12:55

1 stop12h 25m

London Luton

Thu 11/12

06:00-17:20

1 stop17h 20m

£376

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 30/9

19:10-09:05

Nonstop7h 55m

London Heathrow

Fri 14/11

15:45-18:45

Nonstop9h 00m

£382

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 2/12

21:45-11:35

Nonstop7h 50m

London Heathrow

Wed 10/12

11:00-13:50

Nonstop8h 50m

£382

ChicagoLondon

ORD - LGW

ORDLGW

Chicago O'Hare Intl

Sun 8/2

18:30-10:55

1 stop10h 25m

London Gatwick

Fri 20/2

11:55-17:20

1 stop11h 25m

£382

ChicagoLondon

ORD - LGW

ORDLGW

Chicago O'Hare Intl

Tue 10/2

18:30-10:55

1 stop10h 25m

London Gatwick

Tue 17/2

11:55-17:20

1 stop11h 25m

£382

ChicagoLondon

ORD - LGW

ORDLGW

Chicago O'Hare Intl

Tue 10/2

18:30-10:55

1 stop10h 25m

London Gatwick

Sat 21/2

11:55-17:20

1 stop11h 25m

£382

Flights are sorted by cheapest return flights first.

Deals found on 10/9

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

Have a flexible travel schedule? Discover the best time to fly to London 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

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

Currently, January is the cheapest month in which you can book a flight from Illinois to London (average of £112). Flying from Illinois to London 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 LON?

Find hourly flight availability from Illinois to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 12 September 2025.

When flying from Illinois to London, 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

Explore weekly flight availability from Illinois to London. 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 12 September 2025.

The most flights from USIL to LON are scheduled on a Tuesday (57 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (52 on average).

Related info for your journey

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

    Departing from Illinois to London will take you 8h 10m. Illinois and London are separated by a distance of 3939 mi. This flight may include one or multiple stops.

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

    £175 is the cheapest one-way deal found within the past few days, from TAP AIR PORTUGAL. You may also be able to find cheap deals on JetBlue and Scandinavian Airlines, with prices starting from £239 and £255, respectively.

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

    When deciding which route to take from Illinois to London consider Chicago O'Hare Intl - London Heathrow, Chicago O'Hare Intl - London Gatwick or Chicago O'Hare Intl - London City as they are the most popular.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Illinois to London on time: Aer Lingus (64%), American Airlines (62%), Air Canada (62%).

  • What are the cheapest flights from Illinois to London?

    Looking for the cheapest flight from Illinois to London? While on average our users pay £404, our data indicates the cheapest price to be £257. The most popular route (Chicago O'Hare Intl - London Heathrow), is priced around £312.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Illinois to London 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?

    Currently, January is the cheapest month in which you can book a flight from Illinois to London (average of £112). Flying from Illinois to London 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?

Book flights to London if you plan to visit one of these locations
Milton Keynes
Croydon
Hounslow
Gatwick
Slough
Luton
Deal
Wembley
Ilford
Crawley
Hayes
Watford
Folkestone
Winchester
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Ipswich
Dartford
Eastbourne
Guildford
Bishop's Stortford

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Alternative routes for Illinois to London

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 London

Discover the top 7 airlines that operate flights from Illinois to London. 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 12 September 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£355Average£545FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
FinnairCheapest£410Average£645FlexibilityNo cancel feeOn-time76%
Search Finnair flights
IberiaCheapest£442Average£539FlexibilityNo cancel feeOn-time77%
Search Iberia flights
Aer LingusCheapest£445Average£576FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
British AirwaysCheapest£455Average£602FlexibilityNo cancel feeOn-time70%
Search British Airways flights
United AirlinesCheapest£458Average£689FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
American AirlinesCheapest£495Average£623FlexibilityNo cancel feeOn-time71%
Search American 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 London?

Cheapflights helps you search for flights from Illinois to London 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 Illinois to London?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Illinois to London for you. Better yet — we are completely free to use.

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

Certainly. Search results for flights to London from Illinois shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on Illinois to London 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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