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Cheap flights from Illinois to London from £159

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 28/7. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LON
29 Jul — 5 Aug1
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 29 June 2026.

Wed 28/1016:55
ORD
-
LTN
1 stop19h 25m
Multiple Airlines
Sun 1/1114:10
LTN
-
ORD
2 stops32h 35m
Multiple Airlines
Deal found 28/6£679
Wed 12/815:40
ORD
-
LHR
1 stop12h 35m
British Airways
Wed 26/812:15
LHR
-
ORD
Nonstop8h 45m
British Airways
Deal found 26/6£679
Mon 21/916:50
ORD
-
LCY
1 stop10h 00m
Delta
Tue 29/909:20
LCY
-
ORD
1 stop10h 55m
Delta
Deal found 26/6£679
Thu 20/819:50
ORD
-
LGW
2 stops18h 35m
TAP AIR PORTUGAL
Wed 26/821:15
LGW
-
ORD
2 stops21h 25m
TAP AIR PORTUGAL
Deal found 26/6£679
Fri 2/1011:25
ORD
-
STN
1 stop16h 30m
Turkish Airlines
Fri 9/1017:35
STN
-
ORD
1 stop22h 05m
Turkish Airlines
Deal found 29/6£679
Sat 22/814:15
ORD
-
LTN
2 stops14h 05m
Multiple Airlines
Sun 6/909:15
LTN
-
ORD
2 stops18h 10m
Multiple Airlines
Deal found 27/6£679
Tue 15/1220:40
ORD
-
LHR
Nonstop7h 45m
Finnair
Thu 24/1211:00
LHR
-
ORD
Nonstop8h 50m
Finnair
Deal found 29/6£679
Thu 3/919:25
ORD
-
LGW
2 stops17h 00m
Multiple Airlines
Mon 7/915:40
LGW
-
ORD
1 stop32h 35m
Multiple Airlines
Deal found 28/6£679
Mon 24/822:25
ORD
-
STN
2 stops18h 25m
Multiple Airlines
Sat 29/813:15
STN
-
ORD
1 stop12h 00m
Multiple Airlines
Deal found 27/6£679
Mon 20/719:25
ORD
-
LTN
2 stops14h 20m
Multiple Airlines
Fri 24/708:15
LTN
-
ORD
3 stops17h 50m
Multiple Airlines
Deal found 27/6£680
Sat 14/1115:45
ORD
-
LHR
Nonstop8h 10m
United Airlines
Wed 25/1106:50
LHR
-
ORD
1 stop11h 20m
United Airlines
Deal found 26/6£680
Wed 12/814:20
ORD
-
LCY
1 stop12h 20m
SWISS
Tue 15/909:15
LCY
-
ORD
1 stop12h 40m
SWISS
Deal found 26/6£680

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 29 June 2026.

Round-trip from

£679

One-way from

£159

Popular in

June

Cheapest in

September

Average price

£1,047

Good round-trip deal

£674 or less

Good one-way deal

£283 or less
British Airways
  • British Airways
  • 12/8-26/8
  • 1 total stop
  • 21h 20m total
  • Illinois to London
Search Deals
28/7
  • 28/7
  • 1 total stop
  • 35h 51m total
  • Illinois to London
Search Deals
Highest demand for flights based on searches. 26% potential increase in price (£163 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 7% potential price decrease (£31 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 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 29 June 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 - LCY

ORDLCY

Chicago O'Hare Intl

Tue 22/9

16:20-08:50

1 stop10h 30m

London City

Tue 29/9

09:20-14:15

1 stop10h 55m

£679

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Sat 3/10

21:30-11:55

Nonstop8h 25m

London Heathrow

Thu 8/10

07:25-14:05

1 stop12h 40m

£681

ChicagoLondon

ORD - LGW

ORDLGW

Chicago O'Hare Intl

Sun 11/10

18:00-11:20

2 stops59h 20m

London Gatwick

Wed 14/10

16:25-12:40

1 stop26h 15m

£682

ChicagoLondon

ORD - STN

ORDSTN

Chicago O'Hare Intl

Sat 19/9

11:25-09:55

1 stop16h 30m

London Stansted

Tue 29/9

17:35-09:40

1 stop22h 05m

£682

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Thu 16/7

09:50-12:25

2 stops20h 35m

London Luton

Tue 21/7

19:50-19:55

2 stops30h 05m

£684

ChicagoLondon

ORD - LCY

ORDLCY

Chicago O'Hare Intl

Wed 23/9

16:50-08:50

1 stop10h 00m

London City

Wed 7/10

08:25-18:10

2 stops15h 45m

£685

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Thu 10/12

15:45-05:55

Nonstop8h 10m

London Heathrow

Wed 16/12

07:30-15:20

1 stop13h 50m

£688

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Fri 16/10

15:45-08:25

1 stop10h 40m

London Luton

Sun 25/10

14:05-17:45

2 stops32h 40m

£688

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Mon 20/7

19:25-22:50

2 stops21h 25m

London Luton

Fri 24/7

08:15-22:05

2 stops19h 50m

£690

ChicagoLondon

ORD - LTN

ORDLTN

Chicago O'Hare Intl

Thu 24/9

09:50-13:35

3 stops21h 45m

London Luton

Wed 30/9

08:00-12:40

2 stops34h 40m

£694

Flights are sorted by cheapest return flights first.

Deals found on 28/6

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 £495). Flying from Illinois to London in February is currently the most expensive (average of £1,177). 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 29 June 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 29 June 2026.

The most flights from USIL to LON are scheduled on a Monday (56 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (48 on average).

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

How far ahead should I book a flight from Illinois to London?

Booking 32 days in advance of your planned departure date is, on average, the best time to get cheap flights from Illinois to London. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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 25m. 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?

    £168 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 £280 and £289, 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 (72%), Austrian Airlines (72%), United Airlines (72%).

  • What are the cheapest flights from Illinois to London?

    Looking for the cheapest flight from Illinois to London? While on average our users pay £572, our data indicates the cheapest price to be £234. The most popular route (Chicago O'Hare Intl - London Heathrow), is priced around £452.

  • 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 £495). Flying from Illinois to London in February is currently the most expensive (average of £1,177). 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
Hounslow
Milton Keynes
Luton
Wembley
Gatwick
Croydon
Slough
Ilford
Hayes
Brentford
Colchester
Watford
Kingston upon Thames
Eastbourne
Southall
Aylesbury
Romford
Ipswich
Borehamwood
Southend-on-Sea

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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 5 airlines flying from Illinois to London

Discover the top 5 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 29 June 2026.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£371Average£496FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
British AirwaysCheapest£420Average£564FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Aer LingusCheapest£467Average£793FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£517Average£707FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
IberiaCheapest£527Average£675FlexibilityNo 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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