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>

$261 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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Filter your dealsChoose cabin class, free Wi-Fi and more.

Cheapest round-trip

$558

Overall average: $727

Scandinavian Airlines

Sun 1/11Wed 1/21

ORD - LHR • 2 stops

Cheapest non-stop

$569

Typical prices: $709-$1,114

Finnair

Wed 12/10Thu 1/15

ORD - LHR • Non-stop

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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, Jan 11 - Wed, Jan 21

10:29 am - 9:20 amORD-LHR

16h 51m2 stops

10:20 am - 4:45 pmLHR-ORD

12h 25m1 stop

$558Scandinavian Airlines

Find Deal

Sun, Jan 11 - Wed, Jan 21

10:29 am - 9:20 amORD-LHR

16h 51m2 stops

6:40 am - 4:45 pmLHR-ORD

16h 05m1 stop

$559Scandinavian Airlines

Find Deal

Thu, Feb 12 - Sat, Feb 21

7:20 pm - 4:25 pmORD-LHR

15h 05m2 stops

5:30 pm - 4:55 pmLHR-ORD

29h 25m2 stops

$560Scandinavian Airlines

Find Deal

Mon, Jan 12 - Tue, Jan 20

7:20 pm - 6:30 pmORD-LHR

17h 10m1 stop

7:50 pm - 4:45 pmLHR-ORD

26h 55m2 stops

$561Scandinavian Airlines

Find Deal

Wed, Apr 22 - Tue, May 5

5:40 pm - 7:20 amORD-LHR

7h 40mnonstop

10:20 am - 5:50 pmLHR-ORD

13h 30m1 stop

$564Finnair

Find Deal

Wed, Jan 14 - Fri, Jan 23

11:24 am - 8:15 amCMI-LHR

14h 51m1 stop

7:30 am - 6:23 pmLHR-CMI

16h 53m2 stops

$577Iberia

Find Deal

Wed, Mar 11 - Wed, Mar 18

6:00 am - 6:55 amSPI-LHR

19h 55m1 stop

2:55 pm - 11:32 pmLHR-SPI

37h 37m2 stops

$588British Airways

Find Deal

Wed, Dec 10 - Fri, Jan 16

1:50 pm - 7:05 amMDW-LHR

11h 15m1 stop

6:20 am - 10:07 pmLHR-MDW

21h 47m2 stops

$590Delta

Find Deal

Tue, Dec 9 - Thu, Jan 15

12:50 pm - 6:25 amMDW-LHR

11h 35m1 stop

6:30 am - 5:34 pmLHR-MDW

17h 04m2 stops

$591Delta

Find Deal

Tue, Jan 13 - Tue, Jan 20

5:16 pm - 10:25 amPIA-LHR

11h 09m1 stop

2:10 pm - 10:21 pmLHR-PIA

14h 11m1 stop

$596British Airways

Find Deal

Useful Info

Low season	January
High season	July
Cheapest flight	$261

Best time to beat the crowds with an average 11% 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 AirwaysORD-LHRJun 2025

Get a wheel chair if you have difficulty walking

JoeFlew with IberiaORD-LHRApr 2025

Get there early. Nice airport options while you wait.

Verified travelerFlew with IberiaORD-LHRMay 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 AirlinesORD-LHRJan 2025

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

KariFlew with British AirwaysORD-LHRMay 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 AirlinesORD-LHRDec 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

Kingston upon Thames

Eastbourne

Swindon

Colchester

St. Albans

Ipswich

Northampton

Twickenham

Bedford

Everything you need to know for your flight to Heathrow

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London Heathrow Airport (LHR)

LHR

$261 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

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