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.

$306 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

Thu, Oct 29 - Sun, Nov 1

8:15 pm - 12:55 pmORD Chicago O'Hare Intl-LHR London Heathrow

35h 40m2 stops Kastrup Copenhagen Stockholm Arlanda

6:40 am - 5:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 05m1 stop Kastrup Copenhagen

$673Scandinavian Airlines

Fri, Oct 9 - Mon, Oct 12

7:15 pm - 12:55 pmORD Chicago O'Hare Intl-LHR London Heathrow

35h 40m2 stops Kastrup Copenhagen Stockholm Arlanda

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

15h 30m1 stop Kastrup Copenhagen

$673Scandinavian Airlines

Mon, Sep 21 - Tue, Sep 29

7:25 pm - 11:55 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Reykjavik Keflavik Intl

1:05 pm - 6:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 10m1 stop Reykjavik Keflavik Intl

$686Icelandair

Thu, Oct 22 - Thu, Oct 29

7:25 pm - 11:55 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Reykjavik Keflavik Intl

12:15 pm - 6:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

11h 05m1 stop Reykjavik Keflavik Intl

$686Icelandair

Fri, Nov 6 - Fri, Nov 13

8:10 pm - 12:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

34h 30m1 stop Lisbon Humberto Delgado

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

15h 30m1 stop Lisbon Humberto Delgado

$702TAP AIR PORTUGAL

Thu, Oct 1 - Thu, Oct 15

6:00 pm - 10:05 pmORD Chicago O'Hare Intl-LHR London Heathrow

22h 05m1 stop Lisbon Humberto Delgado

4:35 pm - 4:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

29h 25m1 stop Lisbon Humberto Delgado

$702TAP AIR PORTUGAL

Mon, Nov 2 - Tue, Nov 10

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

10h 20m1 stop Reykjavik Keflavik Intl

9:55 am - 3:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

35h 35m2 stops Barcelona-El Prat Lisbon Humberto Delgado

$705Multiple Airlines

Wed, Oct 21 - Wed, Oct 28

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

8h 00mnonstop

3:40 pm - 7:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$711British Airways

Tue, Nov 10 - Thu, Nov 12

4:30 pm - 8:30 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 00m1 stop Toronto Pearson Intl

6:50 am - 2:52 pmLHR London Heathrow-ORD Chicago O'Hare Intl

14h 02m2 stops Brussels Bruxelles-National Montreal Pierre Elliott Trudeau Intl

$712Multiple Airlines

Tue, Sep 29 - Mon, Oct 5

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

$759British Airways

Recent last minute flight deals from Illinois to Heathrow

Wed, Aug 12 - Tue, Sep 15

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

18h 50m1 stop Lisbon Humberto Delgado

7:50 pm - 4:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

26h 10m1 stop Lisbon Humberto Delgado

$755TAP AIR PORTUGAL

Wed, Aug 12 - Tue, Sep 15

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

18h 50m1 stop Lisbon Humberto Delgado

7:50 pm - 4:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

26h 10m1 stop Lisbon Humberto Delgado

$756TAP AIR PORTUGAL

Mon, Aug 10 - Wed, Sep 9

3:45 pm - 8:05 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 20m1 stop Dublin

9:50 am - 8:20 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 30m2 stops Dublin Toronto Pearson Intl

$808Aer Lingus

Tue, Aug 11 - Fri, Aug 21

10:25 pm - 8:20 pmORD Chicago O'Hare Intl-LHR London Heathrow

15h 55m1 stop Reykjavik Keflavik Intl

9:25 pm - 6:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

26h 50m1 stop Reykjavik Keflavik Intl

$904Icelandair

Tue, Aug 11 - Tue, Aug 18

7:25 pm - 11:55 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Reykjavik Keflavik Intl

9:25 pm - 9:25 pmLHR London Heathrow-ORD Chicago O'Hare Intl

30h 00m1 stop Reykjavik Keflavik Intl

$904Icelandair

Wed, Aug 12 - Wed, Aug 19

6:00 am - 9:30 amORD Chicago O'Hare Intl-LHR London Heathrow

21h 30m1 stop New York John F Kennedy Intl

8:15 am - 5:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 20m1 stop New York John F Kennedy Intl

$916JetBlue

Tue, Aug 11 - Wed, Aug 19

6:30 pm - 8:45 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 15m1 stop New York John F Kennedy Intl

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

19h 43m1 stop New York John F Kennedy Intl

$916JetBlue

Tue, Aug 11 - Fri, Aug 21

7:05 pm - 1:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

11h 55m1 stop Zurich

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

12h 35m1 stop Zurich

$975SWISS

Tue, Aug 11 - Wed, Aug 19

2:40 pm - 1:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

16h 20m1 stop Zurich

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

22h 30m1 stop Zurich

$975SWISS

Wed, Aug 12 - Wed, Aug 19

3:45 pm - 8:05 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 20m1 stop Dublin

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

11h 50m1 stop Dublin

$1,030Aer Lingus

Recent direct flight deals from Illinois to Heathrow

Wed, Oct 21 - Wed, Oct 28

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

8h 00mnonstop

3:40 pm - 7:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$711British Airways

Tue, Sep 29 - Mon, Oct 5

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

$759British Airways

Mon, Jan 11 - Wed, Jan 20

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

$830Finnair

Tue, Sep 22 - Tue, Sep 29

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

7h 50mnonstop

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

8h 40mnonstop

$834Finnair

Wed, Nov 18 - Tue, Nov 24

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

$855Iberia

Wed, Nov 18 - Tue, Nov 24

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

$855Iberia

Tue, Nov 3 - Tue, Nov 10

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

$879Aer Lingus

Sun, Nov 8 - Wed, Nov 18

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

8h 10mnonstop

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

9h 20mnonstop

$881United Airlines

Sun, Nov 8 - Fri, Nov 20

5:45 pm - 7:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

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

9h 05mnonstop

$881United Airlines

Wed, Oct 21 - Wed, Oct 28

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

7h 50mnonstop

3:40 pm - 7:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 05mnonstop

$898Aer Lingus

Useful Info

Low season	January
High season	July
Cheapest flight	$306

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

Most popular time to fly with an average 30% 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

Hayes

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Richmond

Wembley

Salisbury

Luton

Eastbourne

Ilford

Crawley

Watford

Bedford

Swindon

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Ipswich

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Twickenham

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London Heathrow Airport (LHR)

LHR

$306 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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Recent last minute 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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