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.

$290 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

Sun, Jan 10 - Sun, Jan 17

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

19h 00m1 stop Reykjavik Keflavik Intl

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

11h 05m1 stop Reykjavik Keflavik Intl

$616Icelandair

Sun, Dec 13 - Sun, Dec 20

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

19h 00m1 stop Reykjavik Keflavik Intl

8:35 pm - 5:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

26h 45m1 stop Reykjavik Keflavik Intl

$654Icelandair

Sun, Oct 11 - Tue, Oct 20

5:27 pm - 12:15 pmSTL Lambert-St Louis-LHR London Heathrow

12h 48m1 stop Chicago O'Hare Intl

11:10 am - 12:19 amLHR London Heathrow-STL Lambert-St Louis

19h 09m1 stop Chicago O'Hare Intl

$715Finnair

Tue, Oct 27 - Tue, Nov 3

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

7h 45mnonstop

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

8h 55mnonstop

$724Finnair

Wed, Sep 30 - Sat, Nov 7

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

10h 30m1 stop Dublin

8:50 am - 2:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 20m1 stop Dublin

$724Aer Lingus

Wed, Sep 30 - Mon, Oct 26

3:45 pm - 9:05 amORD Chicago O'Hare Intl-LHR London Heathrow

11h 20m1 stop Dublin

7:50 am - 3:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 20m1 stop Dublin

$724Aer Lingus

Sun, Sep 27 - Tue, Oct 13

2:01 pm - 6:30 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 29m1 stop Montreal Pierre Elliott Trudeau Intl

6:50 am - 12:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 10m1 stop Brussels Bruxelles-National

$724United Airlines

Mon, Nov 2 - Wed, Nov 18

3:55 pm - 9:00 pmORD Chicago O'Hare Intl-LGW London Gatwick

23h 05m2 stops Dublin Madrid Barajas

4:35 pm - 6:20 pmLGW London Gatwick-ORD Chicago O'Hare Intl

31h 45m3 stops Lisbon Humberto Delgado Madrid Barajas Dublin

$724Multiple Airlines

Sun, Jan 3 - Fri, Jan 8

6:30 pm - 3:05 pmORD Chicago O'Hare Intl-LTN London Luton

14h 35m1 stop Reykjavik Keflavik Intl

6:00 am - 5:20 pmLTN London Luton-ORD Chicago O'Hare Intl

17h 20m1 stop Reykjavik Keflavik Intl

$725Multiple 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

$726United Airlines

Recent last minute flight deals from Illinois to London

Sun, Sep 20 - Tue, Sep 29

9:15 pm - 11:15 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

10:30 am - 4:46 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 16m1 stop New York John F Kennedy Intl

$719British Airways

Sun, Sep 20 - Tue, Sep 29

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

8h 00mnonstop

8:45 am - 4:50 pmLHR London Heathrow-ORD Chicago O'Hare Intl

14h 05m1 stop Paris Charles de Gaulle

$724American Airlines

Sun, Sep 20 - Tue, Sep 29

6:25 pm - 1:15 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 50m1 stop Atlanta Hartsfield-Jackson

8:40 am - 2:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 35m1 stop Amsterdam Schiphol

$725Delta

Sun, Sep 20 - Sun, Oct 11

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

15h 20m1 stop Zurich

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

12h 35m1 stop Zurich

$728SWISS

Sun, Sep 20 - Tue, Oct 6

9:29 am - 1:05 pmMDW Chicago Midway-LHR London Heathrow

21h 36m2 stops Detroit Metropolitan Wayne County Minneapolis St Paul

9:20 am - 4:14 pmLHR London Heathrow-MDW Chicago Midway

12h 54m1 stop Atlanta Hartsfield-Jackson

$728Virgin Atlantic

Sun, Sep 20 - Thu, Jan 28

7:35 am - 6:45 amORD Chicago O'Hare Intl-LHR London Heathrow

17h 10m1 stop Boston Logan Intl

6:30 am - 2:25 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 55m1 stop Amsterdam Schiphol

$729Delta

Sun, Sep 20 - Sun, Oct 11

7:05 pm - 5:50 pmORD Chicago O'Hare Intl-LHR London Heathrow

16h 45m1 stop Zurich

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

12h 35m1 stop Zurich

$729SWISS

Sun, Sep 20 - Tue, Sep 29

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

$730British Airways

Sun, Sep 20 - Tue, Sep 29

9:15 pm - 11:15 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

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

8h 45mnonstop

$730American Airlines

Sun, Sep 20 - Tue, Sep 29

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

18h 15m1 stop Atlanta Hartsfield-Jackson

11:45 am - 10:44 pmLHR London Heathrow-MDW Chicago Midway

16h 59m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson

$739Virgin Atlantic

Recent direct flight deals from Illinois to London

Tue, Oct 27 - Tue, Nov 3

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

7h 45mnonstop

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

8h 55mnonstop

$724Finnair

Wed, Sep 30 - Mon, Oct 5

8:50 pm - 10:50 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

12:15 pm - 3:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$725Finnair

Tue, Nov 10 - Thu, Nov 19

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

$729Aer Lingus

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

$731American Airlines

Mon, Oct 12 - Fri, Oct 23

9:15 pm - 11:15 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

12:15 pm - 3:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$731American Airlines

Sun, Oct 4 - Wed, Nov 11

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

$731United Airlines

Mon, Oct 5 - Tue, Nov 17

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

$731United Airlines

Mon, Dec 7 - Tue, Dec 15

6:50 pm - 8:35 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

$731Iberia

Tue, Sep 29 - Fri, Oct 23

10:25 pm - 12:15 pmORD Chicago O'Hare Intl-LHR London Heathrow

7h 50mnonstop

12:15 pm - 3:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mnonstop

$731Iberia

Mon, Sep 28 - Fri, Oct 9

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

$931Aer Lingus

Useful Info

Low season	February
High season	March
Cheapest flight	$290

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

Ilford

Eastbourne

Crawley

Guildford

Bedford

Colchester

Ipswich

Watford

Kingston upon Thames

Twickenham

St. Albans

Harrow

Newbury

Maidenhead

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$290 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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Flights from Illinois to London: the best tips from KAYAK users

FAQs for booking flights from Illinois to London

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