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. Visit our flight page for the latest deals!>/a>

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. Visit our flight page for the latest deals!>/a>

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. Visit our flight page for the latest deals!>/a>

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. Visit our flight page for the latest deals!>/a>

$360 CHEAP FLIGHTS from Illinois to London Heathrow (LHR)

LHR

KAYAK searches hundreds of travel sites at once for deals on flights to London Heathrow Airport

...and more

Travelers love KAYAK

41,299,237 searches in the past 7 days on KAYAK

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Filter your dealsChoose cabin class, free Wi-Fi and more.

Cheapest round-trip

$545

Overall average: $722

Scandinavian Airlines

Sun 3/15Wed 3/18

ORD - LHR • 1 stop

Cheapest non-stop

$626

Typical prices: $642-$840

British Airways

Sun 2/8Thu 3/5

ORD - LHR • Non-stop

Start a new search

KAYAK searches 100s of sites at once to find you the best travel deals.

We hope you love your trip to Heathrow!

Flight Deals

Cheap Flights from Illinois to Heathrow

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Illinois to Heathrow that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

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

Sun, Mar 15 - Wed, Mar 18

8:20 pm - 4:00 pm

ORD

LHR

14h 40m1 stop

6:40 am - 5:45 pm

LHR

ORD

16h 05m1 stop

$545Scandinavian Airlines

Tue, Jan 6 - Tue, Jan 13

6:30 pm - 10:50 am

ORD

LHR

10h 20m1 stop

12:15 pm - 5:20 pm

LHR

ORD

11h 05m1 stop

$546Icelandair

Fri, Jan 30 - Wed, Feb 4

7:10 pm - 6:30 pm

ORD

LHR

17h 20m2 stops

7:05 am - 4:45 pm

LHR

ORD

15h 40m2 stops

$547Scandinavian Airlines

Fri, Jan 16 - Thu, Jan 29

8:15 pm - 10:40 pm

ORD

LHR

20h 25m1 stop

6:30 pm - 3:25 pm

LHR

ORD

26h 55m1 stop

$554TAP AIR PORTUGAL

Mon, Jan 5 - Tue, Jan 13

1:20 pm - 5:55 am

PIA

LHR

10h 35m1 stop

10:25 am - 4:43 pm

LHR

PIA

12h 18m1 stop

$613Lufthansa

Mon, Jan 5 - Tue, Jan 13

5:19 pm - 5:55 am

PIA

LHR

30h 36m1 stop

6:30 am - 9:39 pm

LHR

PIA

21h 09m2 stops

$617Lufthansa

Fri, Jan 30 - Fri, Feb 6

5:59 pm - 11:40 am

EVV

LHR

11h 41m1 stop

6:30 am - 5:19 pm

LHR

EVV

16h 49m2 stops

$629KLM

Wed, Mar 4 - Mon, Mar 9

5:53 am - 7:50 am

MLI

LHR

19h 57m1 stop

6:30 am - 10:32 pm

LHR

MLI

21h 02m2 stops

$629Delta

Thu, Jan 29 - Thu, Feb 5

11:40 am - 11:40 am

EVV

LHR

18h 00m1 stop

6:30 am - 5:19 pm

LHR

EVV

16h 49m2 stops

$630KLM

Wed, Jan 7 - Thu, Jan 15

6:45 am - 6:25 am

MDW

LHR

17h 40m1 stop

6:30 am - 5:34 pm

LHR

MDW

17h 04m2 stops

$636Delta

Useful Info

Low season	January
High season	July
Cheapest flight	$360

Best time to beat the crowds with an average 10% drop in price.

Most popular time to fly with an average 17% increase in price.

Flight from St. Louis to London Heathrow Airport

Verified travelerFlew with British Airways

ORD

LHR

Jun 2025

Get a wheel chair if you have difficulty walking

JoeFlew with Iberia

ORD

LHR

Apr 2025

Get there early. Nice airport options while you wait.

Verified travelerFlew with Iberia

ORD

LHR

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

ORD

LHR

Jan 2025

Anticipate delays, prepare for long walks through Heathrow to baggage claim or for connections.

KariFlew with British Airways

ORD

LHR

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

ORD

LHR

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

Wembley

Hayes

Richmond

Luton

Ilford

Salisbury

Crawley

Watford

Guildford

Eastbourne

Kingston upon Thames

Swindon

Colchester

Northampton

St. Albans

Ipswich

Twickenham

Bedford

Everything you need to know for your flight to Heathrow

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Complete your trip

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London Heathrow Airport (LHR)

LHR

$360 Find Cheap Flights from Illinois to London Heathrow Airport

KAYAK searches hundreds of travel sites at once for deals on flights to London Heathrow Airport

Everything you should know

Cheap Flights from Illinois to Heathrow

Recent round-trip 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

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

FAQs for booking Illinois to London Heathrow Airport flights

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.

Traveling 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 rental

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