How does KAYAK find such low prices on flights from Illinois to London?

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.

How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to London?

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London 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?

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 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?

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 from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

$207 CHEAP FLIGHTS from Illinois to London

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Cheap Flights from Illinois to London

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 London

Wed, Aug 19 - Wed, Aug 26

3:45 pm - 9:00 am

ORD

LTN

11h 15m

1 stop

6:15 am - 7:52 pm

LTN

ORD

19h 37m

2 stops

$856Multiple Airlines

Tue, Oct 20 - Tue, Oct 27

9:15 pm - 11:15 am

ORD

LHR

8h 00mnonstop

4:30 pm - 8:25 pm

LHR

ORD

8h 55mnonstop

$865Finnair

Wed, Aug 12 - Wed, Aug 19

3:45 pm - 8:05 am

ORD

LHR

10h 20m

1 stop

1:25 pm - 7:15 pm

LHR

ORD

11h 50m

1 stop

$866Aer Lingus

Mon, Oct 12 - Mon, Oct 19

8:10 pm - 10:10 pm

ORD

STN

20h 00m

1 stop

10:50 am - 9:40 am

STN

ORD

28h 50m

1 stop

$866Turkish Airlines

Mon, Aug 24 - Sun, Oct 25

10:25 pm - 2:40 pm

ORD

LGW

10h 15m

1 stop

2:40 pm - 6:20 pm

LGW

ORD

32h 40m

1 stop

$867Icelandair

Sun, Sep 27 - Mon, Oct 5

3:35 pm - 10:10 am

ORD

STN

12h 35m

1 stop

4:25 pm - 6:15 pm

STN

ORD

31h 50m

1 stop

$867Lufthansa

Tue, Sep 15 - Fri, Oct 30

8:10 pm - 10:25 pm

ORD

LGW

20h 15m

1 stop

6:30 am - 7:20 pm

LGW

ORD

17h 50m

1 stop

$869Turkish Airlines

Sun, Jul 26 - Wed, Dec 2

7:25 pm - 11:55 am

ORD

LHR

10h 30m

1 stop

8:35 pm - 5:20 pm

LHR

ORD

26h 45m

1 stop

$872Icelandair

Tue, Nov 3 - Wed, Nov 11

4:20 pm - 9:15 am

ORD

LCY

10h 55m

1 stop

9:50 am - 8:05 pm

LCY

ORD

16h 15m

1 stop

$883Lufthansa

Sat, Sep 19 - Wed, Sep 23

5:18 pm - 1:55 pm

STL

LHR

14h 37m

2 stops

9:50 am - 12:27 am

LHR

STL

20h 37m

2 stops

$1,077Aer Lingus

Useful Info

Low season	February
High season	March
Cheapest flight	$207

Best time to beat the crowds with an average 17% drop in price.

Most popular time to fly and prices are also 15% lower on average.

Flight from St. Louis to London Gatwick Airport

Verified travelerFlew with British Airways

ORD

LHR

Mar 2026

Take early morning flights to adjust to weather-related delays.

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?
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.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to London?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London 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?
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 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?
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 from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Hounslow

Hayes

Slough

Richmond

Wembley

Luton

Crawley

Ilford

Eastbourne

Watford

Bedford

Colchester

Guildford

Kingston upon Thames

Twickenham

Ipswich

St. Albans

Maidenhead

Worthing

Chelmsford

Everything you need to know for your flight to London

Cabin class

Complete your trip

Direct Flights

Flights to other cities

Origins

Other airports

Return flight deals

Cabin class types available on flights to Illinois

First Class flights to Londonfrom $4,990

Business Class flights to Londonfrom $4,276

Premium Economy Class flights to Londonfrom $1,673

Economy Class flights to Londonfrom $856

$207 Find Cheap Flights from Illinois to London - Compare and Save

Cheap Flights from Illinois to London

Recent round-trip flight deals from Illinois to London

Recent one-way flight deals from Illinois to London

Recent last minute flight deals from Illinois to London

Recent direct flight deals from Illinois to London

Good to know

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

FAQs for booking flights from Illinois to London

Traveling to a place near London?

Everything you need to know for your flight to London

Cabin class types available on flights to Illinois

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

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Flights to other popular destinations

Flights from domestic origins to London

Choose which airport to fly into in London

Find deals for your return flight