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 travellers 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 return 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.

£227 CHEAP FLIGHTS from Illinois to London Heathrow (LHR)

Save 25% or more on flights. Compare deals from all over the web.

Never overpay with our price tracking tools.

Filter searches by price, airline and more to find your best flights.

Flight Deals

Cheap Flights from Illinois to Heathrow

Discover the best prices for you by selecting your travel dates on KAYAK.

Return

One-way

Last minute

Direct

Recent return flight deals from Illinois to Heathrow

Fri, 25 Sep - Sun, 27 Sep

19:15 - 18:30ORD Chicago O'Hare Intl-LHR London Heathrow

17h 15m2 stops Kastrup Copenhagen Stockholm Arlanda

17:00 - 16:10LHR London Heathrow-ORD Chicago O'Hare Intl

29h 10m1 stop Kastrup Copenhagen

£493Scandinavian Airlines

Fri, 16 Oct - Fri, 30 Oct

22:25 - 11:55ORD Chicago O'Hare Intl-LHR London Heathrow

31h 30m1 stop Reykjavik Keflavik Intl

15:15 - 19:25LHR London Heathrow-ORD Chicago O'Hare Intl

33h 10m2 stops Paris Orly Dublin

£493Multiple Airlines

Thu, 21 Jan - Thu, 28 Jan

18:30 - 19:30ORD Chicago O'Hare Intl-LHR London Heathrow

19h 00m1 stop Reykjavik Keflavik Intl

12:15 - 17:20LHR London Heathrow-ORD Chicago O'Hare Intl

11h 05m1 stop Reykjavik Keflavik Intl

£508Icelandair

Sat, 17 Oct - Sat, 31 Oct

19:25 - 11:55ORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Reykjavik Keflavik Intl

12:15 - 18:20LHR London Heathrow-ORD Chicago O'Hare Intl

11h 05m1 stop Reykjavik Keflavik Intl

£509Icelandair

Sun, 15 Nov - Wed, 18 Nov

20:50 - 11:20ORD Chicago O'Hare Intl-LHR London Heathrow

32h 30m1 stop Toronto Pearson Intl

06:50 - 12:10LHR London Heathrow-ORD Chicago O'Hare Intl

11h 20m1 stop Brussels Bruxelles-National

£539United Airlines

Mon, 23 Nov - Thu, 26 Nov

20:50 - 08:30ORD Chicago O'Hare Intl-LHR London Heathrow

29h 40m1 stop Toronto Pearson Intl

06:50 - 12:10LHR London Heathrow-ORD Chicago O'Hare Intl

11h 20m1 stop Brussels Bruxelles-National

£539United Airlines

Tue, 29 Sep - Tue, 6 Oct

21:00 - 13:30ORD Chicago O'Hare Intl-LHR London Heathrow

10h 30m1 stop Dublin

07:40 - 14:00LHR London Heathrow-ORD Chicago O'Hare Intl

12h 20m1 stop Dublin

£568Aer Lingus

Tue, 29 Sep - Tue, 6 Oct

15:45 - 08:05ORD Chicago O'Hare Intl-LHR London Heathrow

10h 20m1 stop Dublin

08:50 - 14:00LHR London Heathrow-ORD Chicago O'Hare Intl

11h 10m1 stop Dublin

£568Aer Lingus

Wed, 30 Sep - Wed, 7 Oct

20:50 - 10:50ORD Chicago O'Hare Intl-LHR London Heathrow

8h 00mdirect

09:45 - 12:30LHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mdirect

£595British Airways

Wed, 30 Sep - Wed, 7 Oct

16:01 - 08:30ORD Chicago O'Hare Intl-LHR London Heathrow

10h 29m1 stop New York John F Kennedy Intl

09:45 - 12:30LHR London Heathrow-ORD Chicago O'Hare Intl

8h 45mdirect

£595British Airways

Recent last minute flight deals from Illinois to Heathrow

Sun, 23 Aug - Wed, 2 Sep

18:00 - 12:45ORD Chicago O'Hare Intl-LHR London Heathrow

12h 45m1 stop Lisbon Humberto Delgado

18:45 - 12:40LHR London Heathrow-ORD Chicago O'Hare Intl

23h 55m1 stop Lisbon Humberto Delgado

£604TAP AIR PORTUGAL

Sun, 23 Aug - Fri, 4 Sep

18:00 - 12:45ORD Chicago O'Hare Intl-LHR London Heathrow

12h 45m1 stop Lisbon Humberto Delgado

06:00 - 16:00LHR London Heathrow-ORD Chicago O'Hare Intl

16h 00m1 stop Lisbon Humberto Delgado

£604TAP AIR PORTUGAL

Sun, 23 Aug - Mon, 31 Aug

06:00 - 09:30ORD Chicago O'Hare Intl-LHR London Heathrow

21h 30m1 stop New York John F Kennedy Intl

08:15 - 21:58LHR London Heathrow-ORD Chicago O'Hare Intl

19h 43m1 stop New York John F Kennedy Intl

£654JetBlue

Thu, 20 Aug - Mon, 24 Aug

06:00 - 09:30ORD Chicago O'Hare Intl-LHR London Heathrow

21h 30m1 stop New York John F Kennedy Intl

08:15 - 21:58LHR London Heathrow-ORD Chicago O'Hare Intl

19h 43m1 stop New York John F Kennedy Intl

£654JetBlue

Sun, 23 Aug - Wed, 2 Sep

22:30 - 12:15ORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mdirect

07:50 - 16:00LHR London Heathrow-ORD Chicago O'Hare Intl

14h 10m1 stop Madrid Barajas

£688Iberia

Sun, 23 Aug - Wed, 2 Sep

22:30 - 12:15ORD Chicago O'Hare Intl-LHR London Heathrow

7h 45mdirect

07:50 - 16:00LHR London Heathrow-ORD Chicago O'Hare Intl

14h 10m1 stop Madrid Barajas

£688Iberia

Sun, 23 Aug - Tue, 1 Sep

22:25 - 20:20ORD Chicago O'Hare Intl-LHR London Heathrow

15h 55m1 stop Reykjavik Keflavik Intl

13:05 - 18:15LHR London Heathrow-ORD Chicago O'Hare Intl

11h 10m1 stop Reykjavik Keflavik Intl

£690Icelandair

Sat, 22 Aug - Tue, 22 Sep

15:45 - 09:05ORD Chicago O'Hare Intl-LHR London Heathrow

11h 20m1 stop Dublin

07:40 - 14:00LHR London Heathrow-ORD Chicago O'Hare Intl

12h 20m1 stop Dublin

£744Aer Lingus

Wed, 19 Aug - Wed, 26 Aug

21:00 - 13:55ORD Chicago O'Hare Intl-LHR London Heathrow

10h 55m1 stop Dublin

07:40 - 14:00LHR London Heathrow-ORD Chicago O'Hare Intl

12h 20m1 stop Dublin

£764Aer Lingus

Sun, 23 Aug - Sat, 29 Aug

10:56 - 11:55ORD Chicago O'Hare Intl-LHR London Heathrow

18h 59m2 stops Boston Logan Intl Reykjavik Keflavik Intl

21:25 - 21:25LHR London Heathrow-ORD Chicago O'Hare Intl

30h 00m1 stop Reykjavik Keflavik Intl

£1,237Icelandair

Useful Info

Low season	January
High season	December
Cheapest flight	£227

Best time to beat the crowds (24% less expensive on average)

Most popular time to fly (8% more expensive on average)

Flight from Chicago 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 travellers 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 return 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.

Gatwick

Milton Keynes

Eastbourne

Hounslow

Luton

Southend-on-Sea

Northampton

Winchester

Swindon

Slough

Folkestone

Stansted

Croydon

Newport

Poole

Colchester

Chichester

Maidstone

Crawley

Salisbury

Everything you need to know for your flight to Heathrow

Airports

Cabin class

Complete your trip

Direct flights

Flights to other cities

Origins

Other airports

Return flight deals

Information on your arrival and departure airports

London Heathrow Airport (LHR)

£227 Find Cheap Flights from Illinois to London Heathrow Airport – Compare and Save

Cheap Flights from Illinois to Heathrow

Recent return flight deals from Illinois to Heathrow

Recent one-way flight deals from Illinois to Heathrow

Recent last minute flight deals from Illinois to Heathrow

Recent direct flight deals from Illinois to Heathrow

Good to know - Cheap tickets from Illinois to London Heathrow Airport

Low season

High season

Cheapest flight

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

FAQs for booking Illinois to London Heathrow Airport flights

Travelling to a place near Heathrow?

Everything you need to know for your flight to Heathrow

Information on your arrival and departure airports

Cabin class types available on flights to Heathrow

Complete your trip to Heathrow with a hotel stay or car hire

Find direct flights for Heathrow

Flights to other popular destinations

Flights from domestic origins to Illinois

Choose which airport to fly into in London

Find deals for your return flight