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

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 Heathrow Airport.

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

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport 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 Heathrow Airport?

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 Heathrow Airport 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 Heathrow Airport?

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 Heathrow Airport from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

$304 CHEAP FLIGHTS from Illinois to London Heathrow (LHR)

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Cheap Flights from Illinois to Heathrow

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 Heathrow

Tue, Oct 27 - Mon, Nov 16

7:30 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

$706Icelandair

Mon, Jan 4 - Sun, Feb 28

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

$706Icelandair

Mon, Nov 23 - Thu, Nov 26

7:15 pm - 9:20 amORD Chicago O'Hare Intl-LHR London Heathrow

32h 05m1 stop Kastrup Copenhagen

6:40 am - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 05m2 stops Stockholm Arlanda Kastrup Copenhagen

$706Scandinavian Airlines

Wed, Nov 4 - Wed, Nov 11

6:30 pm - 9:20 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 50m3 stops Reykjavik Keflavik Intl Frankfurt am Main Brussels Bruxelles-National

8:30 am - 5:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

14h 50m2 stops Frankfurt am Main Reykjavik Keflavik Intl

$707Multiple Airlines

Mon, Oct 19 - Mon, Oct 26

7:25 pm - 9:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 15m3 stops Reykjavik Keflavik Intl Oslo Gardermoen Kastrup Copenhagen

7:05 am - 6:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 15m2 stops Oslo Gardermoen Reykjavik Keflavik Intl

$707Multiple Airlines

Mon, Nov 23 - Thu, Nov 26

7:15 pm - 9:20 amORD Chicago O'Hare Intl-LHR London Heathrow

32h 05m1 stop Kastrup Copenhagen

7:05 am - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 40m2 stops Oslo Gardermoen Kastrup Copenhagen

$711Scandinavian Airlines

Fri, Nov 20 - Sat, Nov 28

12:50 pm - 8:30 amORD Chicago O'Hare Intl-LHR London Heathrow

13h 40m1 stop Toronto Pearson Intl

1:00 pm - 7:52 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 52m1 stop Montreal Pierre Elliott Trudeau Intl

$711Air Canada

Sat, Nov 21 - Sun, Nov 29

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

11h 15m1 stop Montreal Pierre Elliott Trudeau Intl

11:10 am - 7:58 pmLHR London Heathrow-ORD Chicago O'Hare Intl

14h 48m1 stop Toronto Pearson Intl

$713Air Canada

Wed, Nov 25 - Mon, Nov 30

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

8h 05mnonstop

3:00 pm - 3:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

30h 10m1 stop Madrid Barajas

$718Iberia

Wed, Oct 28 - Tue, Nov 10

6:40 pm - 12:05 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 25m1 stop Madrid Barajas

10:05 am - 9:54 pmLHR London Heathrow-ORD Chicago O'Hare Intl

17h 49m2 stops Madrid Barajas Boston Logan Intl

$718Iberia

Recent last minute flight deals from Illinois to Heathrow

Tue, Sep 15 - Wed, Oct 7

1:19 pm - 7:10 amMDW Chicago Midway-LHR London Heathrow

11h 51m1 stop Detroit Metropolitan Wayne County

6:15 am - 4:47 pmLHR London Heathrow-MDW Chicago Midway

16h 32m2 stops Paris Charles de Gaulle Minneapolis St Paul

$739Delta

Tue, Sep 15 - Thu, Oct 1

1:19 pm - 7:10 amMDW Chicago Midway-LHR London Heathrow

11h 51m1 stop Detroit Metropolitan Wayne County

3:15 pm - 10:44 pmLHR London Heathrow-MDW Chicago Midway

13h 29m1 stop Atlanta Hartsfield-Jackson

$746Delta

Tue, Sep 15 - Thu, Oct 1

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

$769Virgin Atlantic

Tue, Sep 15 - Thu, Oct 1

1:19 pm - 10:20 amMDW Chicago Midway-LHR London Heathrow

15h 01m2 stops Detroit Metropolitan Wayne County New York John F Kennedy Intl

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

16h 59m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson

$774Virgin Atlantic

Mon, Sep 14 - Sat, Sep 19

7:15 pm - 4:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 45m1 stop Kastrup Copenhagen

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

15h 30m1 stop Kastrup Copenhagen

$841Scandinavian Airlines

Tue, Sep 15 - Wed, Oct 7

1:19 pm - 7:10 amMDW Chicago Midway-LHR London Heathrow

11h 51m1 stop Detroit Metropolitan Wayne County

10:45 am - 6:00 pmLHR London Heathrow-MDW Chicago Midway

13h 15m1 stop Detroit Metropolitan Wayne County

$846Scandinavian Airlines

Sun, Sep 13 - Wed, Sep 16

11:01 am - 7:40 amSTL Lambert-St Louis-LHR London Heathrow

14h 39m1 stop Chicago O'Hare Intl

12:20 pm - 8:20 amLHR London Heathrow-STL Lambert-St Louis

26h 00m2 stops Madrid Barajas Boston Logan Intl

$864Iberia

Wed, Sep 9 - Sat, Sep 12

9:38 am - 6:30 amORD Chicago O'Hare Intl-LHR London Heathrow

14h 52m1 stop Boston Logan Intl

8:15 am - 9:58 pmLHR London Heathrow-ORD Chicago O'Hare Intl

19h 43m1 stop New York John F Kennedy Intl

$872JetBlue

Wed, Sep 9 - Sat, Sep 12

9:38 am - 6:30 amORD Chicago O'Hare Intl-LHR London Heathrow

14h 52m1 stop Boston Logan Intl

11:55 am - 9:58 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 03m1 stop New York John F Kennedy Intl

$872JetBlue

Sun, Sep 13 - Wed, Sep 16

11:01 am - 7:40 amSTL Lambert-St Louis-LHR London Heathrow

14h 39m1 stop Chicago O'Hare Intl

2:45 pm - 11:43 pmLHR London Heathrow-STL Lambert-St Louis

14h 58m1 stop Dallas/Fort Worth

$896Iberia

Recent direct flight deals from Illinois to Heathrow

Wed, Jan 6 - Wed, Jan 20

5:10 pm - 6:55 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

$718British Airways

Thu, Oct 22 - Sat, Oct 24

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

7h 50mnonstop

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

8h 45mnonstop

$718British Airways

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

$731Finnair

Sun, Oct 18 - Wed, Oct 28

6:05 pm - 8:05 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mnonstop

12:35 pm - 4:25 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 50mnonstop

$731Finnair

Wed, Oct 7 - Wed, Oct 21

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

7h 55mnonstop

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

8h 45mnonstop

$731American Airlines

Wed, Oct 7 - Wed, Oct 14

10:30 pm - 12:15 pmORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

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

8h 45mnonstop

$731American Airlines

Tue, Nov 17 - Sun, Nov 22

5:10 pm - 6:55 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

$758Iberia

Mon, Jan 25 - Mon, Feb 1

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

$767Iberia

Wed, Oct 28 - Thu, Nov 12

9:25 pm - 10:25 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

$768Multiple Airlines

Wed, Jan 13 - Mon, Jan 18

6:50 pm - 8:35 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

$880Multiple Airlines

Useful Info

Low season	January
High season	July
Cheapest flight	$304

Best time to beat the crowds with an average 23% drop in price.

Most popular time to fly with an average 26% increase in price.

Flight from Chicago O'Hare Airport to London Heathrow Airport

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 Heathrow Airport?
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 Heathrow Airport.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to London Heathrow Airport?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport 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 Heathrow Airport?
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 Heathrow Airport 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 Heathrow Airport?
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 Heathrow Airport 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

Salisbury

Luton

Ilford

Eastbourne

Crawley

Guildford

Bedford

Colchester

Ipswich

Northampton

Watford

Swindon

Kingston upon Thames

Twickenham

St. Albans

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$304 Find Cheap Flights from Illinois to London Heathrow Airport - Compare and Save

Cheap Flights from Illinois to Heathrow

Recent round-trip flight deals from Illinois to Heathrow

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

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