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Cheap flights from Illinois to London from $284

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Illinois to London departing on 2/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Illinois to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
Icelandair Logo
7:25 pm - 8:20 pm
ORD
-
LHR
18h 55m
1 stop
Icelandair Logo
1:05 pm - 6:15 pm
LHR
-
ORD
11h 10m
1 stop
$518Icelandair
Wed, Apr 22 - Fri, May 1
Icelandair Logo
7:25 pm - 11:55 am
ORD
-
LHR
10h 30m
1 stop
Icelandair Logo
1:05 pm - 6:15 pm
LHR
-
ORD
11h 10m
1 stop
$519Icelandair
Tue, Apr 28 - Tue, May 5
American Airlines Logo
5:00 am - 7:40 am
SPI
-
LHR
20h 40m
1 stop
American Airlines Logo
1:25 pm - 11:34 pm
LHR
-
SPI
16h 09m
2 stops
$595American Airlines
Wed, Apr 1 - Wed, Apr 8
American Airlines Logo
5:00 am - 7:40 am
SPI
-
LHR
20h 40m
1 stop
American Airlines Logo
1:10 pm - 11:34 pm
LHR
-
SPI
16h 24m
2 stops
$597American Airlines
Wed, Apr 1 - Wed, Apr 8
Multiple Airlines Logo
6:37 pm - 11:15 am
SPI
-
LHR
10h 38m
1 stop
Multiple Airlines Logo
6:15 am - 11:34 pm
LHR
-
SPI
23h 19m
2 stops
$616Multiple Airlines
Wed, Apr 1 - Wed, Apr 8
Multiple Airlines Logo
5:00 am - 11:15 am
SPI
-
LHR
24h 15m
1 stop
Multiple Airlines Logo
3:15 pm - 11:34 pm
LHR
-
SPI
14h 19m
1 stop
$618Multiple Airlines
Wed, Apr 1 - Wed, Apr 8
British Airways Logo
6:37 pm - 10:30 am
SPI
-
LHR
9h 53m
1 stop
British Airways Logo
2:45 pm - 11:34 pm
LHR
-
SPI
14h 49m
1 stop
$619British Airways
Wed, Apr 1 - Wed, Apr 8
British Airways Logo
6:37 pm - 10:30 am
SPI
-
LHR
9h 53m
1 stop
British Airways Logo
3:15 pm - 11:34 pm
LHR
-
SPI
14h 19m
1 stop
$620British Airways
Wed, Apr 1 - Wed, Apr 8
Air Canada Logo
4:05 pm - 6:35 am
STL
-
LHR
32h 30m
1 stop
Air Canada Logo
2:10 pm - 8:04 pm
LHR
-
STL
11h 54m
1 stop
$627Air Canada
Sat, Apr 25 - Thu, May 7
Air Canada Logo
4:05 pm - 9:35 am
STL
-
LHR
11h 30m
1 stop
Air Canada Logo
2:05 pm - 3:24 pm
LHR
-
STL
31h 19m
2 stops
$630Air Canada
Mon, Mar 30 - Wed, Apr 8

British Airways flights from Illinois to London Heathrow Airport

Our best British Airways deals on Illinois to London Heathrow Airport flight tickets
British Airways
Apr 17
ORD10:35 pmChicago O'Hare Intl
7h 40m
LHR12:15 pmLondon Heathrow
Apr 19
LHR7:55 amLondon Heathrow
14h 05m
1 stop
ORD4:00 pmChicago O'Hare Intl
$544
British Airways
Feb 2
ORD5:10 pmChicago O'Hare Intl
7h 45m
LHR6:55 amLondon Heathrow
Feb 25
LHR12:50 pmLondon Heathrow
12h 25m
1 stop
ORD7:15 pmChicago O'Hare Intl
$555
British Airways
Feb 18
ORD5:10 pmChicago O'Hare Intl
7h 45m
LHR6:55 amLondon Heathrow
Feb 25
LHR12:10 pmLondon Heathrow
13h 05m
1 stop
ORD7:15 pmChicago O'Hare Intl
$556

TAP AIR PORTUGAL flights from Illinois to London Heathrow Airport

Our best TAP AIR PORTUGAL deals on Illinois to London Heathrow Airport flight tickets
TAP AIR PORTUGAL
Jan 28
ORD7:10 pmChicago O'Hare Intl
14h 20m
1 stop
LHR3:30 pmLondon Heathrow
Feb 1
LHR6:00 amLondon Heathrow
14h 45m
1 stop
ORD2:45 pmChicago O'Hare Intl
$526
TAP AIR PORTUGAL
Jan 23
ORD8:15 pmChicago O'Hare Intl
19h 20m
1 stop
LHR9:35 pmLondon Heathrow
Feb 6
LHR6:00 amLondon Heathrow
15h 25m
1 stop
ORD3:25 pmChicago O'Hare Intl
$536
TAP AIR PORTUGAL
Feb 18
ORD7:10 pmChicago O'Hare Intl
20h 25m
1 stop
LHR9:35 pmLondon Heathrow
Mar 1
LHR6:00 amLondon Heathrow
14h 45m
1 stop
ORD2:45 pmChicago O'Hare Intl
$552

momondo Fare Finder

 
Customize your flight search to find flights from Illinois to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated January 22, 2026.
Use the filters below to find and compare flights from Illinois to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Wed 4/22

7:25 pm-8:20 pm

1 stop18h 55m

London Heathrow

Fri 5/1

1:05 pm-6:15 pm

1 stop11h 10m

$518

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 4/28

7:25 pm-11:55 am

1 stop10h 30m

London Heathrow

Tue 5/5

1:05 pm-6:15 pm

1 stop11h 10m

$519

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

5:00 am-7:40 am

1 stop20h 40m

London Heathrow

Wed 4/8

1:25 pm-11:34 pm

2 stops16h 09m

$595

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

5:00 am-7:40 am

1 stop20h 40m

London Heathrow

Wed 4/8

1:10 pm-11:34 pm

2 stops16h 24m

$597

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

6:37 pm-11:15 am

1 stop10h 38m

London Heathrow

Wed 4/8

6:15 am-11:34 pm

2 stops23h 19m

$616

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

5:00 am-11:15 am

1 stop24h 15m

London Heathrow

Wed 4/8

3:15 pm-11:34 pm

1 stop14h 19m

$618

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

6:37 pm-10:30 am

1 stop9h 53m

London Heathrow

Wed 4/8

2:45 pm-11:34 pm

1 stop14h 49m

$619

SpringfieldLondon

SPI - LHR

SPILHR

Springfield Capital

Wed 4/1

6:37 pm-10:30 am

1 stop9h 53m

London Heathrow

Wed 4/8

3:15 pm-11:34 pm

1 stop14h 19m

$620

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 4/25

4:05 pm-6:35 am

1 stop32h 30m

London Heathrow

Thu 5/7

2:10 pm-8:04 pm

1 stop11h 54m

$627

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 3/30

4:05 pm-9:35 am

1 stop11h 30m

London Heathrow

Wed 4/8

2:05 pm-3:24 pm

2 stops31h 19m

$630

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Illinois to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to London Heathrow Airport?

The month of October is, on average, the cheapest month to fly to London Heathrow Airport from Illinois, with most prices found around $644. If you’re not able to fly to London Heathrow Airport in October, then January is your next best option. Flight prices from Illinois to London Heathrow Airport during January average around $648.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Tuesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $764. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $923.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from Illinois to London Heathrow Airport in the evening for as low as $804. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the afternoon are often more expensive with an average ticket price of $832.

What is the cheapest Illinois to London Heathrow flight route?

Fly from Chicago O'Hare Intl to London Heathrow for the best Illinois - London Heathrow flight prices

How far in advance should I book a flight to London Heathrow Airport?

You are more likely to see cheaper flights to London Heathrow Airport from Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $783 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Illinois for as low as $688 on momondo.

What cabin class options are available on Illinois to London Heathrow flights?

There are 4 cabin classes available to choose from on Illinois to London Heathrow flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Cheap Illinois to London Heathrow Airport flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Illinois to London Heathrow Airport

Best Price Found

$407

Fastest flight time

7h 40m

Direct flights

Every day
The best one-way flight to London Heathrow Airport from Illinois in the past 72 hours is $407. The best round-trip flight deal from Illinois to London Heathrow Airport found on momondo in the last 72 hours is $653.
The fastest flight from Illinois to London Heathrow Airport takes 7h 40m
Direct flights go from Illinois to London Heathrow Airport every day.
Search flight deals

  • When did momondo last update prices for flights from Illinois to London Heathrow Airport?

    Prices for flights from Illinois to London Heathrow Airport were last updated today.

  • How many operators does momondo search for flights from Illinois to London Heathrow Airport?

  • How old do you have to be to fly from Illinois to London Heathrow Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Illinois to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The travel and health documents you'll need for your trip to London Heathrow Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London Heathrow Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Illinois to London Heathrow Airport?

Best airlines flying from Illinois to London Heathrow Airport

Compare and see reviews for airlines that fly from Illinois to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
JetBluePriceFrom $51Free CancellationRating
7.2
2,891 reviews
Search JetBlue flights
SWISSPriceFrom $257Free CancellationRating
7.5
1,856 reviews
Search SWISS flights
Scandinavian AirlinesPriceFrom $331Free CancellationRating
7.3
1,660 reviews
Search Scandinavian Airlines flights
DeltaPriceFrom $345Free CancellationRating
7.9
8,091 reviews
Search Delta flights
TAP AIR PORTUGALPriceFrom $427Free CancellationRating
7.1
2,125 reviews
Search TAP AIR PORTUGAL flights
IcelandairPriceFrom $474Free CancellationRating
7.1
602 reviews
Search Icelandair flights
LufthansaPriceFrom $480Free CancellationRating
6.8
7,744 reviews
Search Lufthansa flights
Aer LingusPriceFrom $499Free CancellationRating
7.2
1,442 reviews
Search Aer Lingus flights
FinnairPriceFrom $516Free CancellationRating
7.6
1,353 reviews
Search Finnair flights
Alaska AirlinesPriceFrom $522Free CancellationRating
8.0
11,780 reviews
Search Alaska Airlines flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Luton
Milton Keynes
Dover
Slough
Guildford
Wembley
Crawley
Dartford
Hayes
Stratford-upon-Avon
Brentwood
Watford
Cobham
Folkestone
Romford
Stansted
Harrow
Croydon

Why use momondo?

Why should I use momondo to find a flight deal from Illinois to London?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Illinois to London. momondo saves you time and could save you money on your trip.

Can I find flights from Illinois to London with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Illinois to London flights to just show those with flexible booking policies.

How can momondo help me find flights from Illinois to London?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to London from Illinois.

I’m not ready to book a flight from Illinois to London right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Illinois to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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