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Cheap flights from Illinois to London from £237

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 26/7. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LON
23 May — 30 May1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Illinois to London

Enter your travel dates to find the best prices.

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 23 April 2026.

Sat 16/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Wed 20/513:05
LHR
-
ORD
1 stop14h 20m
Icelandair
Deal found 19/4£514
Tue 12/519:25
ORD
-
STN
2 stops19h 05m
Multiple Airlines
Tue 19/515:10
STN
-
ORD
2 stops30h 50m
Multiple Airlines
Deal found 20/4£514
Tue 29/919:25
ORD
-
LGW
1 stop13h 15m
Icelandair
Sun 4/1015:40
LGW
-
ORD
1 stop11h 45m
Icelandair
Deal found 20/4£516
Mon 27/419:25
ORD
-
LHR
2 stops18h 30m
Multiple Airlines
Mon 4/506:40
LHR
-
ORD
2 stops17h 35m
Multiple Airlines
Deal found 18/4£517
Wed 30/916:30
ORD
-
LGW
1 stop31h 50m
Multiple Airlines
Tue 6/1013:05
LGW
-
ORD
1 stop24h 56m
Multiple Airlines
Deal found 20/4£517
Tue 12/519:25
ORD
-
LGW
2 stops21h 25m
Multiple Airlines
Tue 19/521:35
LGW
-
ORD
3 stops28h 05m
Multiple Airlines
Deal found 21/4£519
Sat 16/519:25
ORD
-
LHR
1 stop10h 30m
Icelandair
Mon 18/513:05
LHR
-
ORD
1 stop14h 20m
Icelandair
Deal found 19/4£520
Sun 3/522:25
ORD
-
LGW
3 stops28h 15m
Multiple Airlines
Wed 27/520:50
LGW
-
ORD
3 stops28h 50m
Multiple Airlines
Deal found 20/4£520
Sun 3/522:25
ORD
-
STN
2 stops19h 25m
Multiple Airlines
Tue 12/512:30
STN
-
ORD
2 stops33h 30m
Multiple Airlines
Deal found 19/4£520
Sat 24/1020:20
ORD
-
LHR
2 stops32h 15m
Scandinavian Airlines
Tue 27/1006:40
LHR
-
ORD
2 stops16h 05m
Scandinavian Airlines
Deal found 20/4£521
Wed 30/919:25
ORD
-
LGW
1 stop13h 15m
Icelandair
Wed 7/1015:40
LGW
-
ORD
1 stop11h 45m
Icelandair
Deal found 20/4£522
Sat 16/515:45
ORD
-
LHR
1 stop12h 35m
Aer Lingus
Sun 17/513:25
LHR
-
ORD
1 stop11h 50m
Aer Lingus
Deal found 19/4£522

Find flight deals from Illinois to London

Keep the following information in mind while searching for Illinois to London flight deals. Data was last updated 23 April 2026.

Round-trip from

£514

One-way from

£237

Popular in

June

Cheapest in

February

Average price

£515

Good round-trip deal

£668 or less

Good one-way deal

£432 or less
Icelandair
  • Icelandair
  • 16/5-20/5
  • 2 total stops
  • 24h 50m total
  • Illinois to London
Search Deals
British Airways
  • British Airways
  • 26/7
  • Nonstop
  • 8h 00m total
  • Illinois to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (£121 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£21 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 2026
Search Deals
Price to beat on a round-trip flight from Illinois to London (LON).
Search Deals
Price to beat on a one-way flight from Illinois to London (LON).
Search Deals

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 23 April 2026.
Use the filters below to find and compare flights from Illinois to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Tue 9/6

09:55-13:25

3 stops21h 30m

London Luton

Thu 11/6

09:25-18:15

2 stops14h 50m

£595

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Sun 23/8

21:15-11:15

Nonstop8h 00m

London Heathrow

Wed 2/9

10:20-17:50

1 stop13h 30m

£636

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 22/9

17:50-07:40

Nonstop7h 50m

London Heathrow

Thu 1/10

10:20-17:50

1 stop13h 30m

£636
Fastest return journey

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 18/8

18:45-09:00

Nonstop8h 15m

London Heathrow

Tue 25/8

06:50-12:00

1 stop11h 10m

£636

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 2/9

13:30-10:20

2 stops14h 50m

London Heathrow

Fri 11/9

09:55-20:50

2 stops16h 55m

£646

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Sun 3/5

13:06-06:20

1 stop11h 14m

London Heathrow

Tue 12/5

09:55-20:14

2 stops16h 19m

£647

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Wed 7/10

19:25-23:10

3 stops21h 45m

London Luton

Sun 11/10

08:00-14:00

2 stops36h 00m

£650

St. LouisLondon

STL - LGW

STLLGW

Lambert-St Louis

Sun 6/9

10:45-16:00

2 stops23h 15m

London Gatwick

Fri 25/9

10:25-16:55

2 stops36h 30m

£655

ChicagoLondon

ORD - LCY

ORDLCY

Chicago O'Hare Intl

Mon 7/9

16:50-09:30

1 stop10h 40m

London City

Tue 15/9

09:20-14:15

1 stop10h 55m

£659

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Mon 4/5

14:25-07:15

1 stop10h 50m

London Heathrow

Tue 2/6

06:30-14:15

1 stop13h 45m

£662

Flights are sorted by cheapest return flights first.

Deals found on 22/4

Showing 1-10 of 60 resultsSorted by cheapest first
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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, November is the cheapest month in which you can book a flight from Illinois to London (average of £473). Flying from Illinois to London in February is currently the most expensive (average of £890). 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 23 April 2026.

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 23 April 2026.

The most flights from USIL to LON are scheduled on a Wednesday (57 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (54 on average).

How much does it cost for a return flight from Illinois to London?

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. 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?

    £164 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 Lufthansa and British Airways, with prices starting from £274 and £280, 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 Stansted 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: Air Canada (89%), Austrian Airlines (89%), United Airlines (89%).

  • What are the cheapest flights from Illinois to London?

    Looking for the cheapest flight from Illinois to London? While on average our users pay £577, our data indicates the cheapest price to be £358. The most popular route (Chicago O'Hare Intl - London Heathrow), is priced around £435.

  • 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, November is the cheapest month in which you can book a flight from Illinois to London (average of £473). Flying from Illinois to London in February is currently the most expensive (average of £890). 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
Wembley
Croydon
Hounslow
Luton
Gatwick
Ilford
Slough
Hayes
Brentford
Colchester
Watford
Kingston upon Thames
Romford
Eastbourne
Ipswich
Southend-on-Sea
Guildford
Bishop's Stortford
Chelmsford

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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 6 airlines flying from Illinois to London

Discover the top 6 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 23 April 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£356Average£512FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
American AirlinesCheapest£383Average£590FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
British AirwaysCheapest£420Average£623FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Aer LingusCheapest£456Average£601FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£459Average£660FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
IberiaCheapest£515Average£627FlexibilityNo 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 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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