How does KAYAK find such low prices on flights from Illinois to London?

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to London.

How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to London?

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London from Illinois is likely to change within 7 days, so travelers know whether to wait or book now.

What is the Hacker Fare option on flights from Illinois to London?

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to London with an airline and back to Illinois with another airline.

What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to London?

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to London from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

$303 CHEAP FLIGHTS from Illinois to London

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Cheap Flights from Illinois to London

Discover the best prices for you by selecting your travel dates on KAYAK.

Round-trip

One-way

Last minute

Direct

Recent round-trip flight deals from Illinois to London

Sat, Dec 5 - Sun, Dec 6

7:10 pm - 6:50 pmORD Chicago O'Hare Intl-LHR London Heathrow

17h 40m2 stops Kastrup Copenhagen Oslo Gardermoen

9:05 pm - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

25h 40m2 stops Stockholm Arlanda Kastrup Copenhagen

$720Scandinavian Airlines

Fri, Feb 12 - Sun, Feb 14

7:10 pm - 8:55 amORD Chicago O'Hare Intl-LHR London Heathrow

31h 45m2 stops Kastrup Copenhagen Stockholm Arlanda

7:30 pm - 9:33 pmLHR London Heathrow-ORD Chicago O'Hare Intl

32h 03m2 stops Kastrup Copenhagen New York John F Kennedy Intl

$722Scandinavian Airlines

Sun, Mar 7 - Sat, Mar 13

8:10 pm - 9:35 pmORD Chicago O'Hare Intl-LHR London Heathrow

19h 25m1 stop Lisbon Humberto Delgado

7:55 pm - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

25h 35m1 stop Lisbon Humberto Delgado

$722TAP AIR PORTUGAL

Wed, Jan 13 - Wed, Jan 20

7:00 pm - 3:30 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 30m1 stop Lisbon Humberto Delgado

6:00 am - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 30m1 stop Lisbon Humberto Delgado

$722TAP AIR PORTUGAL

Sat, Nov 21 - Sun, Dec 6

9:50 pm - 11:35 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

11:00 am - 1:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$722British Airways

Sun, Nov 8 - Wed, Nov 18

6:30 pm - 10:55 amORD Chicago O'Hare Intl-LGW London Gatwick

10h 25m1 stop Reykjavik Keflavik Intl

11:55 am - 5:20 pmLGW London Gatwick-ORD Chicago O'Hare Intl

11h 25m1 stop Reykjavik Keflavik Intl

$722Icelandair

Tue, Dec 1 - Wed, Dec 9

6:30 pm - 3:40 pmORD Chicago O'Hare Intl-LGW London Gatwick

15h 10m1 stop Reykjavik Keflavik Intl

8:20 am - 5:20 pmLGW London Gatwick-ORD Chicago O'Hare Intl

15h 00m1 stop Reykjavik Keflavik Intl

$722Multiple Airlines

Mon, Jan 4 - Mon, Jan 11

6:30 pm - 10:50 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 20m1 stop Reykjavik Keflavik Intl

12:15 pm - 5:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 05m1 stop Reykjavik Keflavik Intl

$723Icelandair

Thu, Nov 12 - Wed, Nov 18

10:35 am - 11:40 amORD Chicago O'Hare Intl-STN London Stansted

19h 05m2 stops Boston Logan Intl Kastrup Copenhagen

8:15 am - 4:45 pmSTN London Stansted-ORD Chicago O'Hare Intl

14h 30m1 stop Kastrup Copenhagen

$723Multiple Airlines

Wed, Mar 24 - Fri, Apr 2

6:10 pm - 6:55 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

1:10 pm - 3:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$725British Airways

Recent last minute flight deals from Illinois to London

Sat, Oct 3 - Tue, Nov 24

6:05 pm - 9:45 amORD Chicago O'Hare Intl-LGW London Gatwick

33h 40m1 stop Lisbon Humberto Delgado

4:35 pm - 3:30 pmLGW London Gatwick-ORD Chicago O'Hare Intl

28h 55m1 stop Lisbon Humberto Delgado

$722TAP AIR PORTUGAL

Wed, Sep 30 - Mon, Oct 5

7:05 pm - 6:30 pmORD Chicago O'Hare Intl-LHR London Heathrow

17h 25m2 stops Zurich Geneva Geneve-Cointrin

8:05 pm - 12:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

22h 30m1 stop Zurich

$722SWISS

Sat, Oct 3 - Tue, Nov 24

6:05 pm - 10:20 amORD Chicago O'Hare Intl-LHR London Heathrow

34h 15m1 stop Lisbon Humberto Delgado

6:30 pm - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

27h 00m1 stop Lisbon Humberto Delgado

$723TAP AIR PORTUGAL

Mon, Oct 5 - Mon, Oct 19

7:05 pm - 4:25 pmORD Chicago O'Hare Intl-LHR London Heathrow

15h 20m1 stop Zurich

7:30 pm - 1:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

23h 50m1 stop Vienna Intl

$727Multiple Airlines

Mon, Oct 5 - Mon, Oct 19

2:20 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

11h 35m1 stop Zurich

7:30 pm - 1:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

23h 50m1 stop Vienna Intl

$727Multiple Airlines

Wed, Sep 30 - Mon, Oct 5

2:20 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

11h 35m1 stop Zurich

8:55 am - 12:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

33h 40m2 stops Geneva Geneve-Cointrin Zurich

$730SWISS

Mon, Oct 5 - Tue, Oct 20

7:15 pm - 9:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 25m1 stop Kastrup Copenhagen

6:40 am - 4:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 30m1 stop Kastrup Copenhagen

$809Scandinavian Airlines

Mon, Oct 5 - Tue, Oct 20

7:15 pm - 9:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 25m1 stop Kastrup Copenhagen

6:40 am - 4:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 30m1 stop Kastrup Copenhagen

$809Scandinavian Airlines

Fri, Oct 2 - Sat, Oct 10

5:00 pm - 6:50 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 50mnonstop

3:15 pm - 6:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 00mnonstop

$857British Airways

Wed, Sep 30 - Wed, Oct 7

7:05 pm - 9:05 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

11:10 am - 1:50 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 40mnonstop

$1,045British Airways

Recent direct flight deals from Illinois to London

Sat, Nov 21 - Sun, Dec 6

9:50 pm - 11:35 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

11:00 am - 1:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$722British Airways

Wed, Nov 25 - Tue, Dec 29

9:50 pm - 11:35 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

11:00 am - 1:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$725British Airways

Wed, Jan 20 - Mon, Jan 25

3:45 pm - 5:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

10:25 am - 1:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 20mnonstop

$791United Airlines

Wed, Jan 20 - Mon, Feb 8

9:50 pm - 12:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

10:25 am - 1:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 20mnonstop

$791United Airlines

Wed, Jan 20 - Mon, Jan 25

6:50 pm - 8:35 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

4:30 pm - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$795Iberia

Mon, Nov 9 - Mon, Nov 16

3:45 pm - 5:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

1:35 pm - 4:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 20mnonstop

$795Lufthansa

Sun, Oct 25 - Tue, Nov 3

10:50 pm - 11:35 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

3:40 pm - 6:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$841Finnair

Mon, Oct 26 - Tue, Nov 3

9:25 pm - 10:25 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

4:30 pm - 7:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 00mnonstop

$846Finnair

Thu, Jan 14 - Mon, Jan 18

8:40 pm - 10:25 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

4:30 pm - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$855Iberia

Sun, Oct 25 - Tue, Nov 3

4:45 pm - 5:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

1:35 pm - 4:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 20mnonstop

$894Lufthansa

Useful Info

Low season	February
High season	March
Cheapest flight	$303

Best time to beat the crowds with an average 21% drop in price.

Most popular time to fly and prices are also 17% lower on average.

Flight from Chicago O'Hare Airport to London Heathrow Airport

JKFlew with American Airlines-Sep 2026

Ask ahead of time, if the aircraft can provide AC and/or oxygen to passengers after boarding.

Verified travelerFlew with British Airways-Mar 2026

Take early morning flights to adjust to weather-related delays.

Verified travelerFlew with British Airways-Jun 2025

Get a wheel chair if you have difficulty walking

JoeFlew with Iberia-Apr 2025

Get there early. Nice airport options while you wait.

Verified travelerFlew with Iberia-May 2025

Get to the airport early so you’re relaxed. Con yourself into believing it’s bedtime and try to sleep so that you can keep going all day when you get there. If you can afford more comfy seats it might be worth it - though I always have the cheap ones so I can’t say for sure. Try very hard not to. sit in the middle. I’m small and the guy next to me played games all night and didn’t care that he continually ( with every move) jabbed me with his arm. This was my first flight with Cheap Flights and it was far less convenient than other times I’ve flown overseas.

DinaFlew with United Airlines-Jan 2025

Anticipate delays, prepare for long walks through Heathrow to baggage claim or for connections.

KariFlew with British Airways-May 2024

Always check to confirm your assistance is in system. No wheelchair waiting for me in London. Had no clue about airport or how to get around. Got lost easy

AaronFlew with American Airlines-Dec 2023

Find a flight where you are allowed to choose your seats before the day of boarding for anything international.

How does KAYAK find such low prices on flights from Illinois to London?
KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to London.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to London?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London from Illinois is likely to change within 7 days, so travelers know whether to wait or book now.
What is the Hacker Fare option on flights from Illinois to London?
Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to London with an airline and back to Illinois with another airline.
What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to London?
Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to London from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Hounslow

Hayes

Slough

Richmond

Wembley

Luton

Eastbourne

Ilford

Guildford

Bedford

Kingston upon Thames

Crawley

Watford

Twickenham

Harrow

St. Albans

Ipswich

Folkestone

Colchester

Horley

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$303 Find Cheap Flights from Illinois to London - Compare and Save

Cheap Flights from Illinois to London

Recent round-trip flight deals from Illinois to London

Recent one-way flight deals from Illinois to London

Recent last minute flight deals from Illinois to London

Recent direct flight deals from Illinois to London

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Cheapest flight

Flights from Illinois to London: the best tips from KAYAK users

FAQs for booking flights from Illinois to London

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Complete your trip to London with a hotel stay or car rental

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