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>

$314 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

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Cheapest round-trip

$519

Typical prices: $639-$874

Icelandair

Tue 4/21Sat 5/2

ORD - LHR • 1 stop

Cheapest non-stop

$621

Typical prices: $665-$778

British Airways

Sun 2/8Tue 2/17

ORD - LHR • Non-stop

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We hope you love your trip to Heathrow!

Flight Deals

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, Apr 21 - Sat, May 2

7:25 pm - 11:55 am

ORD

LHR

10h 30m

1 stop

1:05 pm - 6:15 pm

LHR

ORD

11h 10m

1 stop

$519Icelandair

Fri, Apr 24 - Fri, May 1

10:25 pm - 8:20 pm

ORD

LHR

15h 55m

1 stop

9:25 pm - 6:15 pm

LHR

ORD

26h 50m

1 stop

$521Icelandair

Tue, Feb 24 - Wed, Mar 4

5:22 pm - 10:55 pm

MLI

LHR

23h 33m

2 stops

7:40 am - 9:27 pm

LHR

MLI

19h 47m

2 stops

$617Lufthansa

Tue, Feb 24 - Wed, Mar 4

5:22 pm - 6:35 pm

MLI

LHR

19h 13m

2 stops

8:45 am - 9:27 pm

LHR

MLI

18h 42m

2 stops

$620Lufthansa

Sat, Apr 11 - Wed, Apr 22

4:05 pm - 6:35 am

STL

LHR

32h 30m

1 stop

6:30 am - 1:25 pm

LHR

STL

12h 55m

1 stop

$629Multiple Airlines

Wed, Mar 4 - Thu, Mar 12

7:41 am - 9:20 am

STL

LHR

19h 39m

2 stops

11:10 am - 11:51 pm

LHR

STL

17h 41m

2 stops

$630Multiple Airlines

Tue, Feb 24 - Wed, Mar 4

5:55 am - 7:50 am

MLI

LHR

19h 55m

1 stop

6:30 am - 4:16 pm

LHR

MLI

15h 46m

2 stops

$631KLM

Tue, Feb 24 - Wed, Mar 4

5:55 am - 9:00 am

MLI

LHR

21h 05m

1 stop

6:30 am - 4:16 pm

LHR

MLI

15h 46m

2 stops

$634KLM

Sun, Feb 8 - Tue, Feb 17

4:30 pm - 11:40 am

MDW

LHR

13h 10m

1 stop

6:30 am - 5:37 pm

LHR

MDW

17h 07m

2 stops

$638Delta

Sun, Feb 8 - Thu, Mar 5

1:26 pm - 8:45 am

MDW

LHR

13h 19m

1 stop

8:40 am - 6:40 pm

LHR

MDW

16h 00m

2 stops

$640Delta

Useful Info

Low season	January
High season	July
Cheapest flight	$314

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

Most popular time to fly with an average 18% 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

Hayes

Wembley

Richmond

Luton

Salisbury

Ilford

Crawley

Watford

Guildford

Eastbourne

Kingston upon Thames

Swindon

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Ipswich

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London Heathrow Airport (LHR)

LHR

$314 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

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

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