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.

$320 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, Nov 17 - Tue, Nov 24

7:10 pm - 4:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 50m1 stop Kastrup Copenhagen

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

16h 05m1 stop Kastrup Copenhagen

$724Scandinavian Airlines

Fri, Jan 22 - Fri, Jan 29

8:10 pm - 5:30 pmORD Chicago O'Hare Intl-LHR London Heathrow

15h 20m1 stop Lisbon Humberto Delgado

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

15h 30m1 stop Lisbon Humberto Delgado

$724TAP AIR PORTUGAL

Fri, Jan 22 - Sun, Jan 31

8:10 pm - 5:30 pmORD Chicago O'Hare Intl-LHR London Heathrow

15h 20m1 stop Lisbon Humberto Delgado

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

15h 30m1 stop Lisbon Humberto Delgado

$724TAP AIR PORTUGAL

Wed, Nov 11 - Tue, Nov 17

7:10 pm - 4:00 pmORD Chicago O'Hare Intl-LHR London Heathrow

14h 50m1 stop Kastrup Copenhagen

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

15h 40m2 stops Oslo Gardermoen Kastrup Copenhagen

$725Scandinavian Airlines

Mon, Jan 18 - Tue, Jan 19

2:55 pm - 6:55 amORD Chicago O'Hare Intl-LHR London Heathrow

10h 00m1 stop Boston Logan Intl

9:20 am - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

37h 25m1 stop Boston Logan Intl

$730JetBlue

Wed, Nov 4 - Wed, Nov 11

7:10 pm - 9:10 amORD Chicago O'Hare Intl-LHR London Heathrow

32h 00m3 stops Kastrup Copenhagen Stockholm Arlanda Helsinki-Vantaa

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

16h 05m2 stops Stockholm Arlanda Kastrup Copenhagen

$730Multiple Airlines

Tue, Mar 30 - Thu, Apr 1

9:30 pm - 11:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 25mnonstop

8:45 am - 3:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 10m1 stop Zurich

$731United Airlines

Mon, Feb 8 - Wed, Feb 10

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

8h 10mnonstop

9:00 am - 4:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 15m1 stop Zurich

$731United Airlines

Mon, Jan 18 - Wed, Jan 20

10:33 am - 7:10 amORD Chicago O'Hare Intl-LHR London Heathrow

14h 37m1 stop Montreal Pierre Elliott Trudeau 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

$744Air Canada

Mon, Jan 4 - Thu, Jan 7

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

29h 40m1 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

$778Air Canada

Recent last minute flight deals from Illinois to Heathrow

Fri, Oct 9 - Wed, Oct 28

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

$746Icelandair

Thu, Oct 8 - Wed, Oct 28

9:15 pm - 11:15 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

$771British Airways

Tue, Oct 13 - Tue, Dec 1

7:15 pm - 9:40 pmORD Chicago O'Hare Intl-LHR London Heathrow

20h 25m1 stop Kastrup Copenhagen

10:20 am - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 25m1 stop Kastrup Copenhagen

$780Scandinavian Airlines

Tue, Oct 13 - Wed, Dec 2

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

14h 45m1 stop Kastrup Copenhagen

7:30 pm - 4:45 pmLHR London Heathrow-ORD Chicago O'Hare Intl

27h 15m1 stop Kastrup Copenhagen

$783Scandinavian Airlines

Fri, Oct 9 - 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

$824British Airways

Sat, Oct 10 - Tue, Oct 20

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

14h 52m1 stop Boston Logan Intl

8:40 am - 7:14 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 34m1 stop Boston Logan Intl

$871JetBlue

Sun, Oct 11 - Thu, Oct 15

6:10 am - 9:30 amORD Chicago O'Hare Intl-LHR London Heathrow

21h 20m1 stop New York John F Kennedy Intl

11:55 am - 10:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

16h 15m1 stop New York John F Kennedy Intl

$872JetBlue

Mon, Oct 12 - Thu, Oct 15

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

11h 20m1 stop Dublin

12:00 pm - 7:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

13h 15m1 stop Dublin

$917Aer Lingus

Mon, Oct 12 - Wed, Oct 14

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

11h 20m1 stop Dublin

7:40 am - 2:00 pmLHR London Heathrow-ORD Chicago O'Hare Intl

12h 20m1 stop Dublin

$920Aer Lingus

Mon, Oct 12 - Sat, Dec 12

7:25 pm - 8:20 pmORD Chicago O'Hare Intl-LHR London Heathrow

18h 55m1 stop Reykjavik Keflavik Intl

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

11h 05m1 stop Reykjavik Keflavik Intl

$936Icelandair

Recent direct flight deals from Illinois to Heathrow

Thu, Mar 18 - Mon, Mar 29

10:50 pm - 11:35 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

$812British Airways

Thu, Mar 25 - Sun, Apr 4

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

7h 45mnonstop

3:15 pm - 6:15 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 00mnonstop

$813British Airways

Tue, Jan 5 - Fri, Jan 29

8:05 pm - 10:00 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 55mnonstop

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

9h 05mnonstop

$865Finnair

Wed, Jan 6 - Wed, Feb 17

8:40 pm - 10:25 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

$865Finnair

Wed, Jan 6 - Tue, Jan 12

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

$865Iberia

Tue, Jan 26 - Tue, Feb 2

6:50 pm - 8:35 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

$865Iberia

Tue, Jan 5 - Tue, Jan 12

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

$891American Airlines

Tue, Mar 16 - Wed, Mar 24

6:10 pm - 6:55 amORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mnonstop

11:15 am - 3:10 pmLHR London Heathrow-ORD Chicago O'Hare Intl

8h 55mnonstop

$892American Airlines

Tue, Mar 9 - Tue, Mar 16

3:45 pm - 5:55 amORD Chicago O'Hare Intl-LHR London Heathrow

8h 10mnonstop

1:35 pm - 5:55 pmLHR London Heathrow-ORD Chicago O'Hare Intl

9h 20mnonstop

$892United Airlines

Tue, Jan 5 - Tue, Feb 16

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

$892United Airlines

Useful Info

Low season	January
High season	July
Cheapest flight	$320

Best time to beat the crowds with an average 24% drop in price.

Most popular time to fly with an average 24% increase in price.

Flight from Chicago O'Hare Airport to London Heathrow 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 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

Eastbourne

Ilford

Guildford

Northampton

Swindon

Kingston upon Thames

Bedford

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Ipswich

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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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