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.

$265 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

Wed, Dec 2 - Tue, Dec 8

12:02 pm - 6:50 amSTL Lambert-St Louis-LGW London Gatwick

36h 48m2 stops Atlanta Hartsfield-Jackson Orlando

9:35 am - 12:12 amLGW London Gatwick-STL Lambert-St Louis

20h 37m1 stop Orlando

$642Multiple Airlines

Wed, Dec 2 - Tue, Dec 8

12:02 pm - 6:50 amSTL Lambert-St Louis-LGW London Gatwick

36h 48m2 stops Atlanta Hartsfield-Jackson Orlando

9:35 am - 12:12 amLGW London Gatwick-STL Lambert-St Louis

20h 37m1 stop Orlando

$643Multiple Airlines

Mon, Mar 15 - Mon, Mar 22

7:50 pm - 1:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 10m1 stop Zurich

7:30 pm - 5:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

26h 45m2 stops Geneva Geneve-Cointrin Zurich

$723SWISS

Wed, Jan 20 - Mon, Jan 25

1:55 pm - 7:10 amORD Chicago O'Hare Intl-LHR London Heathrow

11h 15m1 stop Montreal Pierre Elliott Trudeau Intl

12:05 pm - 4:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

34h 10m1 stop Zurich

$723United Airlines

Wed, Feb 3 - Mon, Feb 8

7:05 am - 7:10 amORD Chicago O'Hare Intl-LHR London Heathrow

18h 05m1 stop Montreal Pierre Elliott Trudeau Intl

12:05 pm - 4:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

34h 10m1 stop Zurich

$723United Airlines

Wed, Jan 20 - Tue, Jan 26

5:40 pm - 12:05 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 25m1 stop Madrid Barajas

7:40 pm - 2:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

25h 15m1 stop Madrid Barajas

$723Iberia

Sat, Oct 10 - Wed, Oct 14

9:00 pm - 1:30 pmORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Dublin

1:25 pm - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 50m1 stop Dublin

$723Aer Lingus

Fri, Oct 9 - Wed, Oct 14

9:00 pm - 3:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 00m1 stop Dublin

1:25 pm - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 50m1 stop Dublin

$723Aer Lingus

Tue, Oct 6 - Tue, Nov 17

2:40 pm - 8:25 amORD Chicago O'Hare Intl-LGW London Gatwick

11h 45m1 stop Zurich

8:40 am - 4:15 pmLGW London Gatwick-ORD Chicago O'Hare Intl

13h 35m1 stop Zurich

$724SWISS

Fri, Nov 27 - Fri, Dec 4

6:30 pm - 8:35 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 05mnonstop

7:30 am - 2:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 25m1 stop Madrid Barajas

$724Iberia

Recent last minute flight deals from Illinois to London

Mon, Sep 28 - Sun, Oct 4

2:20 pm - 8:25 amORD Chicago O'Hare Intl-LGW London Gatwick

12h 05m1 stop Zurich

6:35 pm - 12:35 pmLGW London Gatwick-ORD Chicago O'Hare Intl

24h 00m1 stop Zurich

$723SWISS

Mon, Sep 28 - Tue, Oct 6

1:55 pm - 7:10 amORD Chicago O'Hare Intl-LHR London Heathrow

11h 15m1 stop Detroit Metropolitan Wayne County

6:30 am - 2:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 45m1 stop Amsterdam Schiphol

$727Virgin Atlantic

Mon, Sep 28 - Thu, Oct 22

4:25 pm - 6:45 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 20mnonstop

6:00 am - 12:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 35m1 stop Zurich

$728SWISS

Mon, Sep 28 - Tue, Oct 20

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

$729American Airlines

Mon, Sep 28 - Tue, Oct 6

5:55 pm - 7:40 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

9:45 am - 12:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$729American Airlines

Mon, Sep 28 - Tue, Oct 6

4:25 pm - 6:45 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 20mnonstop

8:00 am - 11:10 amLHR London Heathrow-ORD Chicago O'Hare Intl

9h 10mnonstop

$729United Airlines

Mon, Sep 28 - Tue, Oct 6

10:40 am - 6:30 amORD Chicago O'Hare Intl-LHR London Heathrow

13h 50m1 stop Ottawa

9:30 am - 8:12 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 42m1 stop Montreal Pierre Elliott Trudeau Intl

$732Air Canada

Mon, Sep 28 - Tue, Oct 6

10:40 am - 6:30 amORD Chicago O'Hare Intl-LHR London Heathrow

13h 50m1 stop Ottawa

9:30 am - 6:46 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 16m2 stops Montreal Pierre Elliott Trudeau Intl Ottawa

$732Air Canada

Sun, Sep 27 - Tue, Oct 6

1:00 pm - 1:15 pmMDW Chicago Midway-LHR London Heathrow

18h 15m1 stop Atlanta Hartsfield-Jackson

8:55 am - 10:33 pmLHR London Heathrow-MDW Chicago Midway

19h 38m2 stops Paris Charles de Gaulle Atlanta Hartsfield-Jackson

$734Virgin Atlantic

Sun, Sep 27 - Fri, Jan 29

6:35 pm - 9:00 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 25mnonstop

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

9h 20mnonstop

$735United Airlines

Recent direct flight deals from Illinois to London

Mon, Mar 22 - Tue, Mar 30

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

Tue, Feb 16 - Tue, Mar 2

5:10 pm - 6:55 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

Mon, Oct 19 - Fri, Nov 13

4:25 pm - 6:45 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 20mnonstop

7:40 am - 10:45 amLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$729United Airlines

Sun, Oct 18 - Fri, Nov 13

4:25 pm - 6:45 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 20mnonstop

7:40 am - 10:45 amLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$729United Airlines

Wed, Oct 21 - Thu, Nov 5

6:00 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 55mnonstop

12:35 pm - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 55mnonstop

$729Iberia

Wed, Oct 7 - Tue, Nov 17

6:00 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 55mnonstop

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

9h 00mnonstop

$729Iberia

Wed, Oct 28 - Tue, Nov 3

7:35 pm - 8:35 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

12:35 pm - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 55mnonstop

$729American Airlines

Mon, Nov 2 - Thu, Nov 12

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

8h 00mnonstop

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

8h 45mnonstop

$729American Airlines

Mon, Nov 2 - Wed, Nov 11

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

8h 00mnonstop

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

9h 05mnonstop

$729Finnair

Wed, Oct 7 - Tue, Oct 13

6:00 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 55mnonstop

2:45 pm - 5:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 50mnonstop

$729Finnair

Useful Info

Low season	February
High season	March
Cheapest flight	$265

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 St. Louis to London Gatwick 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

Slough

Hayes

Richmond

Wembley

Luton

Eastbourne

Ilford

Crawley

Guildford

Colchester

Ipswich

Kingston upon Thames

Bedford

Watford

Harrow

Twickenham

Newbury

St. Albans

Maidenhead

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$265 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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High season

Cheapest flight

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

FAQs for booking flights from Illinois to London

Traveling to a place near London?

More options for your flight to London

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

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