How long is the flight from Illinois to London Heathrow Airport?

For as low as £648, Scandinavian Airlines can have you in London Heathrow Airport from Illinois in 8h. The distance from Illinois to London Heathrow Airport is about 3939 mi. This flight may include one or multiple stops.

What are the cheapest airlines to fly from Illinois to London Heathrow Airport one-way?

The cheapest airline one-way is Iberia, with whom users have recently found tickets for as low as £287. However, be on the lookout for offers from Lufthansa and British Airways, as they are both options that can get you from Illinois to London Heathrow Airport for a low price.

In terms of precipitation, rainfall in London Heathrow Airport ranges from 40.0 - 70.0 inches per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London Heathrow Airport when rainfall is around 40.0 mm.

If weather is an important factor for your trip to London Heathrow Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 C).

What are the most popular routes from Illinois to London Heathrow Airport?

The most popular route from Illinois to London Heathrow Airport is Chicago O'Hare Intl - London Heathrow. You may also consider Chicago Midway - London Heathrow or Lambert-St Louis - London Heathrow.

What are the cheapest flights from Illinois to London Heathrow Airport?

On average you can expect to pay £752 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £272 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £458.

What are the most reliable airlines from Illinois to London Heathrow Airport?

No one likes to see their flight delayed. When booking a flight from Illinois to London Heathrow Airport consider choosing Royal Jordanian (85%), Air Canada (80%) or Austrian Airlines (80%) as they are the most reliable in getting you off to your destination on time.

What are the most popular airlines that fly from Illinois to London Heathrow Airport?

Consider British Airways, Aer Lingus or United Airlines when booking your flight. These represent the most popular airlines when flying from Illinois to London Heathrow Airport.

Can I find deals for flights from Illinois to Heathrow that include hotel bookings?

Yes. In addition to deals on Illinois to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.

How can I find direct flights from Illinois to Heathrow?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Heathrow.

Can I find deals for business class flights from Illinois to Heathrow?

Yes. Cheapflights offers flight deals from Illinois to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

£236+ Cheap Flights from Illinois to London Heathrow Airport

Cheap flight deals from Illinois to Heathrow

Enter your travel dates to find the best prices.

Cheapest

Best

Direct

Last-minute

One-way

Cheapest flights from Illinois to Heathrow
Explore the most affordable flight options available from Illinois to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 25 October 2026.

Sat 24/1019:05 -

Nonstop8h 00m

Mon 26/1011:00 -

Nonstop8h 45m

Deal found 20/10£532

Tue 20/1017:00 -

Nonstop7h 50m

Thu 29/1015:40 -

Nonstop9h 05m

Deal found 20/10£533

Sun 15/1118:30 -

2 stops20h 35m

Tue 24/1108:50 -

2 stops14h 30m

Deal found 20/10£535

Tue 1/1218:30 -

2 stops15h 05m

Tue 15/1207:50 -

2 stops15h 30m

Deal found 20/10£536

Sat 24/1022:50 -

Nonstop7h 45m

Sat 31/1015:40 -

Nonstop9h 05m

Deal found 20/10£538

Sun 29/1118:30 -

1 stop10h 20m

Tue 8/1212:15 -

1 stop11h 05m

Deal found 22/10£539

Tue 20/1017:00 -

Nonstop7h 50m

Wed 28/1011:00 -

Nonstop8h 45m

Deal found 20/10£539

Tue 20/1017:00 -

Nonstop7h 50m

Sun 25/1015:40 -

Nonstop9h 05m

Deal found 20/10£542

Sun 29/1118:30 -

2 stops19h 20m

Tue 8/1207:50 -

2 stops15h 30m

Deal found 21/10£542

Thu 22/1017:00 -

Nonstop7h 50m

Thu 29/1015:40 -

Nonstop9h 05m

Deal found 20/10£543

Fri 23/1017:00 -

Nonstop7h 50m

Fri 30/1015:40 -

Nonstop9h 05m

Deal found 20/10£544

Fri 23/1017:00 -

Nonstop7h 50m

Thu 29/1015:40 -

Nonstop9h 05m

Deal found 20/10£545

Best flights from Illinois to Heathrow
Discover carefully curated flight deals from Illinois to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 25 October 2026.

Sun 8/1119:10 -

1 stop17h 20m

Fri 13/1119:50 -

2 stops26h 55m

Deal found 23/10£607

Wed 21/422:00 -

Nonstop8h 00m

Wed 28/410:20 -

1 stop13h 30m

Deal found 22/10£648

Fri 26/216:20 -

1 stop34h 00m

Mon 1/307:50 -

Nonstop9h 05m

Deal found 22/10£665

Wed 27/119:00 -

1 stop14h 30m

Sat 6/218:30 -

1 stop27h 00m

Deal found 21/10£674

Tue 1/1221:50 -

Nonstop7h 45m

Fri 11/1207:30 -

1 stop13h 25m

Deal found 22/10£675

Wed 17/318:16 -

1 stop12h 19m

Tue 23/316:30 -

1 stop12h 37m

Deal found 23/10£717

Sat 9/119:10 -

2 stops17h 40m

Sun 24/119:30 -

1 stop27h 15m

Deal found 22/10£639

Thu 11/215:45 -

Nonstop8h 10m

Mon 15/213:45 -

1 stop32h 30m

Deal found 22/10£684

Fri 11/1219:10 -

2 stops31h 45m

Wed 16/1207:05 -

2 stops15h 50m

Deal found 23/10£665

Wed 17/310:56 -

2 stops15h 14m

Tue 23/313:00 -

2 stops15h 13m

Deal found 23/10£755

Sun 21/309:42 -

2 stops22h 18m

Tue 30/306:55 -

2 stops16h 56m

Deal found 20/10£689

Thu 10/1219:10 -

2 stops20h 10m

Sun 13/1206:40 -

2 stops22h 17m

Deal found 24/10£682

Tue 23/318:55 -

2 stops31h 15m

Tue 30/307:25 -

2 stops16h 26m

Deal found 20/10£690

Sun 21/316:00 -

1 stop15h 15m

Sat 27/314:45 -

1 stop24h 49m

Deal found 24/10£803

Sat 20/318:55 -

2 stops33h 15m

Tue 30/307:25 -

2 stops16h 26m

Deal found 20/10£691

Sat 20/318:16 -

1 stop12h 19m

Thu 25/316:30 -

1 stop12h 37m

Deal found 20/10£944

Fri 12/319:10 -

1 stop14h 50m

Sat 20/315:35 -

2 stops31h 10m

Deal found 24/10£714

Mon 22/307:00 -

1 stop17h 55m

Tue 30/313:50 -

2 stops37h 26m

Deal found 22/10£695

Tue 8/1215:45 -

Nonstop8h 10m

Wed 13/107:40 -

Nonstop9h 05m

Deal found 20/10£696

Tue 8/1218:57 -

1 stop11h 03m

Tue 15/1207:30 -

2 stops16h 40m

Deal found 24/10£702

Tue 24/1117:45 -

Nonstop8h 10m

Tue 1/1209:00 -

1 stop13h 15m

Deal found 24/10£707

Sun 21/318:55 -

1 stop12h 05m

Thu 25/310:25 -

1 stop12h 26m

Deal found 20/10£716

Tue 8/1217:30 -

2 stops16h 20m

Tue 15/1209:00 -

2 stops18h 00m

Deal found 24/10£741

Sat 5/1218:57 -

1 stop28h 58m

Sat 12/1211:05 -

2 stops37h 04m

Deal found 21/10£744

Sat 16/119:00 -

2 stops30h 10m

Sat 23/116:40 -

2 stops31h 26m

Deal found 24/10£750

Mon 7/1210:45 -

2 stops17h 20m

Mon 14/1211:05 -

2 stops35h 40m

Deal found 23/10£751

Sun 21/318:55 -

1 stop12h 05m

Fri 26/307:40 -

1 stop15h 11m

Deal found 20/10£752

Sun 6/1217:30 -

1 stop12h 30m

Sun 13/1213:45 -

2 stops37h 15m

Deal found 22/10£776

Sat 7/1118:57 -

2 stops30h 13m

Tue 10/1106:50 -

2 stops17h 20m

Deal found 24/10£789

Mon 30/1114:35 -

2 stops13h 30m

Tue 8/1209:00 -

2 stops18h 00m

Deal found 23/10£862

Find flight deals from Illinois to Heathrow

Round-trip from	£531
One-way from	£236
Popular in	June
Cheapest in	February
Average price	£664
Good round-trip deal	£705 or less
Good one-way deal	£275 or less

Scandinavian Airlines
2/3-7/3
2 total stops
27h 15m total
Illinois to London

Search Deals

25/11-31/12
2 total stops
17h 15m total
Illinois to London

Search Deals

Highest demand for flights based on searches. 21% potential increase in price (£132 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 5% potential price decrease (£26 potential savings vs. average return price).

Search Deals

Average for round-trip flights in October 2026

Search Deals

Price to beat on a round-trip flight from Illinois to London Heathrow.

Search Deals

Price to beat on a one-way flight from Illinois to London Heathrow.

Search Deals

Cheapflights Fare Finder

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

Cheapest return flight

PeoriaLondon

PIA Greater Peoria - LHR London Heathrow

PIALHR

Greater Peoria

Mon 22/3

18:16-11:35

1 stop12h 19m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£265

Fastest return journey

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Thu 11/3

21:50-11:35

Nonstop7h 45m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£284

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Thu 5/11

13:00-06:55

1 stop11h 55m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£294

DecaturLondon

DEC Decatur Arpt - LHR London Heathrow

DECLHR

Decatur Arpt

Fri 12/3

09:42-10:05

2 stops18h 23m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£306

DecaturLondon

DEC Decatur Arpt - LHR London Heathrow

DECLHR

Decatur Arpt

Sun 29/11

09:10-05:55

1 stop14h 45m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£368

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Tue 3/11

09:59-07:15

2 stops15h 16m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£458

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Tue 3/11

17:29-21:35

3 stops22h 06m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£485

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Mon 2/11

19:43-21:35

3 stops19h 52m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£533

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Wed 4/11

21:50-12:00

Nonstop8h 10m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£536

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Sun 22/11

21:50-11:35

Nonstop7h 45m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£544

Flights are sorted by cheapest return flights first.

Deals found on 22/10

Showing 1-10 of 50 resultsSorted by cheapest first

...

Best time to book a flight from Illinois to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Illinois with our price prediction graph.

ORD-LHR

PIA-LHR

DEC-LHR

Estimated return price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Illinois to London Heathrow Airport

USIL-LHR

ORD-LHR

PIA-LHR

DEC-LHR

What is the cheapest month to book a flight from Illinois to London Heathrow Airport?

Currently, January is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £464). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £1,036). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to LHR?

When flying from Illinois to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight from Illinois to London Heathrow Airport?

Airfare is typical for this route at the moment.

Illinois to London Heathrow Airport flights typically cost between £531 and £751 in March.
The cheapest return price found within the last 5 days was £531 on Scandinavian Airlines (2 Mar–7 Mar).

How far ahead should I book a flight from Illinois to London Heathrow Airport?

The price you pay for your flight from Illinois to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 65 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

Related info for your journey

How long is the flight from Illinois to London Heathrow Airport?
For as low as £648, Scandinavian Airlines can have you in London Heathrow Airport from Illinois in 8h. The distance from Illinois to London Heathrow Airport is about 3939 mi. This flight may include one or multiple stops.
What are the cheapest airlines to fly from Illinois to London Heathrow Airport one-way?
The cheapest airline one-way is Iberia, with whom users have recently found tickets for as low as £287. However, be on the lookout for offers from Lufthansa and British Airways, as they are both options that can get you from Illinois to London Heathrow Airport for a low price.
What are the most popular routes from Illinois to London Heathrow Airport?
The most popular route from Illinois to London Heathrow Airport is Chicago O'Hare Intl - London Heathrow. You may also consider Chicago Midway - London Heathrow or Lambert-St Louis - London Heathrow.
What are the most reliable airlines from Illinois to London Heathrow Airport?
No one likes to see their flight delayed. When booking a flight from Illinois to London Heathrow Airport consider choosing Royal Jordanian (85%), Air Canada (80%) or Austrian Airlines (80%) as they are the most reliable in getting you off to your destination on time.
What are the cheapest flights from Illinois to London Heathrow Airport?
On average you can expect to pay £752 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £272 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £458.
Can I find deals for flights from Illinois to Heathrow that include hotel bookings?
Yes. In addition to deals on Illinois to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.
How can I find direct flights from Illinois to Heathrow?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Heathrow.
Can I find deals for business class flights from Illinois to Heathrow?
Yes. Cheapflights offers flight deals from Illinois to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Illinois to London Heathrow Airport?
Currently, January is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £464). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £1,036). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Top 7 airlines flying from Illinois to Heathrow

Airline	Cheapest	Average	Flexibility	On-time
Icelandair	Cheapest£366	Average£564	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
British Airways	Cheapest£455	Average£738	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
Aer Lingus	Cheapest£460	Average£810	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
American Airlines	Cheapest£490	Average£856	FlexibilityNo cancel fee	On-time71%	Search American Airlines flights
United Airlines	Cheapest£510	Average£916	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights
Iberia	Cheapest£520	Average£705	FlexibilityNo cancel fee	On-time77%	Search Iberia flights
JetBlue	Cheapest£743	Average£885	FlexibilityNo cancel fee	On-time62%	Search JetBlue flights

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How does Cheapflights help users find flights from Illinois to Heathrow?

When you search for this flight from Illinois to Heathrow, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Illinois to Heathrow?

By finding flights from multiple airlines and providers at completely no cost, Cheapflights helps millions of users like you annually find the best flights to Heathrow from Illinois.

Can Cheapflights find flights from Illinois to Heathrow with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Illinois to Heathrow, users can toggle the no change fees filter when performing a flight search.

Can Cheapflights notify me if prices for flights from Illinois to Heathrow become cheaper?

Yes, Cheapflights offers price alerts on Illinois to Heathrow flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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Cheap flights from Illinois to London Heathrow Airport from £236

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 25/11. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Illinois to Heathrow

Cheapest flights from Illinois to HeathrowExplore the most affordable flight options available from Illinois to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 25 October 2026.

Explore the most affordable flight options available from Illinois to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 25 October 2026.

Best flights from Illinois to HeathrowDiscover carefully curated flight deals from Illinois to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 25 October 2026.

Discover carefully curated flight deals from Illinois to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 25 October 2026.

Direct flights from Illinois to HeathrowExplore direct flight options from Illinois to Heathrow based on user searches, and compare prices and availability for your desired travel dates. Data last updated 25 October 2026.

Explore direct flight options from Illinois to Heathrow based on user searches, and compare prices and availability for your desired travel dates. Data last updated 25 October 2026.

Last-minute flights from Illinois to HeathrowDiscover last-minute flight deals from Illinois to Heathrow. Data last updated 25 October 2026 and is based on user searches.

Discover last-minute flight deals from Illinois to Heathrow. Data last updated 25 October 2026 and is based on user searches.

One-way flights from Illinois to HeathrowSearch for one-way flight options from Illinois to Heathrow. Find affordable one-way fares based on user searches. Data last updated 25 October 2026.

Search for one-way flight options from Illinois to Heathrow. Find affordable one-way fares based on user searches. Data last updated 25 October 2026.

Find flight deals from Illinois to Heathrow

Round-trip from

One-way from

Popular in

Cheapest in

Average price

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Good one-way deal

Cheapflights Fare Finder

Use the filters below to find and compare flights from Illinois to London Heathrow Airport that are best for you.

Best time to book a flight from Illinois to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Illinois with our price prediction graph.

Cheapflights Insights

What is the cheapest month to book a flight from Illinois to London Heathrow Airport?

What is the cheapest time of day to fly from IL to LHR?

Find hourly flight availability from Illinois to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 25 October 2026.

When flying from Illinois to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight from Illinois to London Heathrow Airport?

Airfare is typical for this route at the moment.

Illinois to London Heathrow Airport flights typically cost between £531 and £751 in March.The cheapest return price found within the last 5 days was £531 on Scandinavian Airlines (2 Mar–7 Mar).

How far ahead should I book a flight from Illinois to London Heathrow Airport?

The price you pay for your flight from Illinois to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 65 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

Related info for your journey

How long is the flight from Illinois to London Heathrow Airport?

What are the cheapest airlines to fly from Illinois to London Heathrow Airport one-way?

What are the most popular routes from Illinois to London Heathrow Airport?

What are the most reliable airlines from Illinois to London Heathrow Airport?

What are the cheapest flights from Illinois to London Heathrow Airport?

Can I find deals for flights from Illinois to Heathrow that include hotel bookings?

How can I find direct flights from Illinois to Heathrow?

Can I find deals for business class flights from Illinois to Heathrow?

What is the cheapest month to book a flight from Illinois to London Heathrow Airport?

Travelling to a place near London Heathrow Airport?

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Alternative routes for Illinois to Heathrow

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Can Cheapflights notify me if prices for flights from Illinois to Heathrow become cheaper?

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Cheapest flights from Illinois to Heathrow
Explore the most affordable flight options available from Illinois to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 25 October 2026.

Best flights from Illinois to Heathrow
Discover carefully curated flight deals from Illinois to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 25 October 2026.

Direct flights from Illinois to Heathrow
Explore direct flight options from Illinois to Heathrow based on user searches, and compare prices and availability for your desired travel dates. Data last updated 25 October 2026.

Last-minute flights from Illinois to Heathrow
Discover last-minute flight deals from Illinois to Heathrow. Data last updated 25 October 2026 and is based on user searches.

One-way flights from Illinois to Heathrow
Search for one-way flight options from Illinois to Heathrow. Find affordable one-way fares based on user searches. Data last updated 25 October 2026.

Illinois to London Heathrow Airport flights typically cost between £531 and £751 in March.
The cheapest return price found within the last 5 days was £531 on Scandinavian Airlines (2 Mar–7 Mar).