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.

$299 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

Fri, Oct 9 - Mon, Oct 12

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

42h 40m2 stops Kastrup Copenhagen Stockholm Arlanda

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

15h 30m1 stop Kastrup Copenhagen

$661Scandinavian Airlines

Wed, Oct 14 - Mon, Oct 19

3:00 pm - 3:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

18h 40m1 stop Rome Fiumicino

9:50 am - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 25m1 stop Dublin

$661Multiple Airlines

Fri, Jan 15 - Tue, Jan 19

7:15 pm - 8:55 amORD Chicago O'Hare Intl-LHR London Heathrow

55h 40m2 stops Kastrup Copenhagen Stockholm Arlanda

6:40 am - 9:33 pmLHR London Heathrow-ORD Chicago O'Hare Intl

20h 53m2 stops Kastrup Copenhagen New York John F Kennedy Intl

$662Scandinavian Airlines

Wed, Sep 30 - Tue, Feb 2

7:25 pm - 5:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

16h 15m2 stops Reykjavik Keflavik Intl Kastrup Copenhagen

9:50 am - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

15h 25m1 stop Dublin

$663Multiple Airlines

Sun, Sep 27 - Sun, Oct 4

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

$673Icelandair

Tue, Sep 29 - Sun, Oct 4

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

$673Icelandair

Thu, Oct 8 - Thu, Oct 15

6:00 pm - 12:45 pmORD Chicago O'Hare Intl-LHR London Heathrow

12h 45m1 stop Lisbon Humberto Delgado

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

26h 10m1 stop Lisbon Humberto Delgado

$680TAP AIR PORTUGAL

Sun, Sep 20 - Tue, Sep 29

6:00 pm - 10:20 amORD Chicago O'Hare Intl-LHR London Heathrow

34h 20m1 stop Lisbon Humberto Delgado

6:45 pm - 4:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

27h 15m1 stop Lisbon Humberto Delgado

$687TAP AIR PORTUGAL

Wed, Sep 30 - Tue, Oct 6

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

$722British Airways

Sun, Sep 27 - Mon, Oct 5

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

$724British Airways

Recent last minute flight deals from Illinois to Heathrow

Wed, Aug 26 - Tue, Mar 23

4:40 pm - 12:45 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 05m1 stop Lisbon Humberto Delgado

6:30 pm - 4:30 pmLHR London Heathrow-ORD Chicago O'Hare Intl

27h 00m1 stop Lisbon Humberto Delgado

$852TAP AIR PORTUGAL

Thu, Aug 27 - Mon, Sep 21

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

16h 00m1 stop Lisbon Humberto Delgado

8:10 pm - 2:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

23h 50m1 stop Dublin

$864Multiple Airlines

Wed, Aug 26 - Wed, Sep 2

4:40 pm - 12:45 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 05m1 stop Lisbon Humberto Delgado

1:45 pm - 12:40 pmLHR London Heathrow-ORD Chicago O'Hare Intl

28h 55m1 stop Lisbon Humberto Delgado

$878TAP AIR PORTUGAL

Wed, Aug 26 - Sun, Aug 30

4:40 pm - 12:45 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 05m1 stop Lisbon Humberto Delgado

9:10 pm - 2:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

22h 50m1 stop Dublin

$885Multiple Airlines

Wed, Aug 26 - Mon, Aug 31

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

15h 55m1 stop Reykjavik Keflavik Intl

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

30h 00m1 stop Reykjavik Keflavik Intl

$909Icelandair

Wed, Aug 26 - Sun, Aug 30

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

15h 55m1 stop Reykjavik Keflavik Intl

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

11h 10m1 stop Reykjavik Keflavik Intl

$937Icelandair

Wed, Aug 26 - Mon, Aug 31

2:20 pm - 11:20 amORD Chicago O'Hare Intl-LHR London Heathrow

15h 00m1 stop Zurich

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

22h 30m1 stop Zurich

$977SWISS

Wed, Aug 26 - Mon, Aug 31

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

11h 35m1 stop Zurich

6:40 pm - 12:35 pmLHR London Heathrow-ORD Chicago O'Hare Intl

23h 55m1 stop Zurich

$978SWISS

Wed, Aug 26 - Wed, Sep 2

12:27 pm - 9:20 amSTL Lambert-St Louis-LHR London Heathrow

14h 53m1 stop Newark

6:30 am - 1:25 pmLHR London Heathrow-STL Lambert-St Louis

12h 55m1 stop Frankfurt am Main

$1,014Lufthansa

Wed, Aug 26 - Wed, Sep 2

9:30 am - 6:45 amSTL Lambert-St Louis-LHR London Heathrow

15h 15m1 stop Chicago O'Hare Intl

6:30 am - 1:25 pmLHR London Heathrow-STL Lambert-St Louis

12h 55m1 stop Frankfurt am Main

$1,017Lufthansa

Recent direct flight deals from Illinois to Heathrow

Wed, Sep 30 - Tue, Oct 6

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

$722British Airways

Sun, Sep 27 - Mon, Oct 5

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

$724British Airways

Wed, Feb 10 - Wed, Feb 24

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

$837Finnair

Mon, Sep 21 - Tue, Sep 29

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

7h 50mnonstop

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

8h 40mnonstop

$838Finnair

Wed, Jan 13 - Sun, Jan 17

9:50 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

$840Iberia

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

$840Iberia

Wed, Nov 18 - Thu, Nov 26

3:45 pm - 5:55 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

$880United Airlines

Wed, Nov 18 - Tue, Nov 24

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

$880United Airlines

Wed, Nov 18 - Wed, Nov 25

8:40 pm - 10:25 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

$880American Airlines

Mon, Dec 7 - Fri, Dec 11

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

$883American Airlines

Useful Info

Low season	January
High season	July
Cheapest flight	$299

Best time to beat the crowds with an average 22% drop in price.

Most popular time to fly with an average 27% 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.

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Richmond

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Salisbury

Luton

Ilford

Eastbourne

Crawley

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Watford

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London Heathrow Airport (LHR)

LHR

$299 Find Cheap Flights from Illinois to London Heathrow Airport - Compare and Save

Cheap Flights from Illinois to Heathrow

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

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