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

For as low as £606, Scandinavian Airlines can have you in London Heathrow Airport from Illinois in 18h 07m. The distance from Illinois to London Heathrow Airport is about 4069 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 American Airlines, 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 £730 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £230 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £405.

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 (88%), Air Canada (84%) or Austrian Airlines (84%) 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.

£239+ 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 9 November 2026.

Thu 10/1219:10 -

2 stops56h 25m

Mon 14/1206:40 -

2 stops40h 05m

Deal found 9/11£489

Mon 7/1218:30 -

2 stops20h 50m

Fri 11/1206:40 -

2 stops16h 40m

Deal found 9/11£505

Sun 6/1218:30 -

2 stops20h 50m

Thu 10/1219:50 -

3 stops27h 30m

Deal found 7/11£508

Tue 1/1218:30 -

1 stop10h 20m

Wed 9/1212:15 -

1 stop35h 05m

Deal found 9/11£515

Tue 1/1218:30 -

1 stop19h 00m

Tue 8/1212:15 -

1 stop35h 05m

Deal found 8/11£515

Wed 9/1219:10 -

2 stops56h 25m

Sun 13/1206:40 -

1 stop16h 05m

Deal found 9/11£516

Wed 25/1118:30 -

1 stop19h 00m

Wed 2/1212:15 -

1 stop35h 05m

Deal found 9/11£518

Tue 17/1118:30 -

3 stops33h 05m

Tue 24/1106:40 -

2 stops16h 40m

Deal found 4/11£521

Wed 2/1218:30 -

1 stop19h 00m

Wed 9/1212:15 -

1 stop35h 05m

Deal found 6/11£523

Sun 6/1218:30 -

1 stop19h 00m

Thu 10/1212:15 -

1 stop35h 05m

Deal found 6/11£524

Mon 7/1217:30 -

1 stop12h 30m

Tue 15/1209:00 -

2 stops31h 10m

Deal found 9/11£730

Sun 6/1219:00 -

2 stops37h 45m

Tue 15/1206:30 -

2 stops16h 15m

Deal found 7/11£737

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 9 November 2026.

Fri 5/219:10 -

2 stops32h 25m

Thu 18/219:50 -

2 stops26h 55m

Deal found 5/11£524

Mon 1/310:43 -

2 stops18h 07m

Wed 3/309:00 -

2 stops18h 14m

Deal found 5/11£606

Wed 27/119:00 -

1 stop21h 40m

Sun 31/106:00 -

1 stop15h 30m

Deal found 9/11£631

Sun 13/1218:30 -

1 stop10h 20m

Wed 13/120:35 -

1 stop26h 45m

Deal found 6/11£635

Wed 10/207:10 -

1 stop17h 15m

Sat 20/208:40 -

1 stop11h 45m

Deal found 5/11£693

Wed 17/316:00 -

1 stop15h 15m

Tue 23/315:40 -

1 stop13h 26m

Deal found 8/11£729

Sat 6/319:10 -

1 stop17h 20m

Sat 13/315:35 -

2 stops31h 10m

Deal found 6/11£547

Fri 19/221:50 -

Nonstop8h 10m

Sun 21/209:00 -

1 stop13h 15m

Deal found 8/11£629

Wed 10/310:30 -

2 stops23h 30m

Wed 17/318:05 -

2 stops28h 40m

Deal found 6/11£608

Mon 29/321:30 -

Nonstop8h 25m

Mon 5/413:50 -

1 stop32h 05m

Deal found 4/11£654

Wed 7/416:25 -

Nonstop8h 20m

Mon 12/416:25 -

1 stop27h 35m

Deal found 8/11£664

Thu 11/315:45 -

Nonstop8h 10m

Fri 19/309:00 -

1 stop13h 15m

Deal found 7/11£689

Sat 10/416:25 -

Nonstop8h 20m

Wed 21/406:50 -

1 stop11h 10m

Deal found 8/11£693

Mon 4/117:45 -

Nonstop8h 10m

Mon 29/312:10 -

1 stop33h 45m

Deal found 7/11£697

Mon 22/210:43 -

1 stop19h 17m

Fri 26/209:00 -

2 stops19h 58m

Deal found 7/11£700

Mon 7/1214:36 -

2 stops14h 14m

Tue 15/1209:00 -

2 stops31h 10m

Deal found 9/11£730

Sun 21/208:08 -

1 stop15h 47m

Sat 27/209:00 -

2 stops19h 58m

Deal found 5/11£736

Sat 5/1218:57 -

1 stop28h 58m

Sat 12/1212:05 -

2 stops49h 50m

Deal found 5/11£741

Sun 6/1210:45 -

1 stop15h 10m

Tue 15/1210:25 -

1 stop16h 35m

Deal found 7/11£765

Sat 5/1214:36 -

1 stop33h 19m

Sat 12/1213:45 -

2 stops37h 15m

Deal found 5/11£783

Wed 23/1219:03 -

2 stops19h 32m

Wed 30/1207:40 -

1 stop16h 16m

Deal found 8/11£867

Sun 22/1118:57 -

1 stop30h 58m

Thu 26/1113:45 -

2 stops34h 25m

Deal found 5/11£889

Fri 11/1208:31 -

1 stop15h 24m

Mon 4/109:30 -

2 stops38h 36m

Deal found 5/11£958

Mon 21/1214:35 -

1 stop15h 25m

Mon 28/1210:25 -

1 stop12h 38m

Deal found 6/11£1,072

Wed 17/309:42 -

2 stops16h 28m

Tue 23/313:00 -

2 stops24h 15m

Deal found 9/11£4,937

Sun 21/309:42 -

2 stops16h 28m

Sat 27/313:00 -

2 stops24h 46m

Deal found 6/11£4,937

Find flight deals from Illinois to Heathrow

Round-trip from	£486
One-way from	£239
Popular in	June
Cheapest in	February
Average price	£592
Good round-trip deal	£819 or less
Good one-way deal	£246 or less

12/1-20/1
6 total stops
50h 05m total
Illinois to London

Search Deals

Iberia
15/2-31/12
Nonstop
7h 45m total
Illinois to London

Search Deals

Highest demand for flights based on searches. 20% potential increase in price (£127 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 5% potential price decrease (£25 potential savings vs. average return price).

Search Deals

Average for round-trip flights in November 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

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Sun 21/2

14:35-10:50

2 stops14h 15m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£249

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Sat 24/4

21:30-21:20

1 stop17h 50m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£249

PeoriaLondon

PIA Greater Peoria - LHR London Heathrow

PIALHR

Greater Peoria

Mon 22/3

14:33-06:55

1 stop11h 22m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£268

Fastest return journey

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Thu 22/4

21:30-11:55

Nonstop8h 25m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£283

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Mon 11/1

14:55-21:35

2 stops24h 40m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£381

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Mon 18/1

14:55-21:35

2 stops24h 40m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£408

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Sun 24/1

14:55-22:40

2 stops25h 45m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£408

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Wed 30/12

06:25-06:25

1 stop18h 00m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£420

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Sat 23/1

14:55-18:55

2 stops22h 00m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£423

ChicagoLondon

ORD Chicago O'Hare Intl - LHR London Heathrow

ORDLHR

Chicago O'Hare Intl

Thu 3/12

17:46-11:25

2 stops35h 39m

London Heathrow

Wed 31/12

00:00-17:00

Nonstop0h 00m

£433

Flights are sorted by cheapest return flights first.

Deals found on 6/11

Showing 1-10 of 41 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 £483). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £1,038). 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.

Weekly flight availability from Illinois to London Heathrow Airport

The most flights from USIL to LHR are scheduled on a Friday (45 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (38 on average).

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

Airfare is below average for this route at the moment.

Illinois to London Heathrow Airport flights typically cost between £547 and £869 in January.
The cheapest return price found within the last 5 days was £486 on Multiple Airlines (12 Jan–20 Jan).

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 £606, Scandinavian Airlines can have you in London Heathrow Airport from Illinois in 18h 07m. The distance from Illinois to London Heathrow Airport is about 4069 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 American Airlines, 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 (88%), Air Canada (84%) or Austrian Airlines (84%) 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 £730 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £230 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £405.
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 £483). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £1,038). 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£368	Average£650	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
British Airways	Cheapest£471	Average£778	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
United Airlines	Cheapest£509	Average£870	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights
Iberia	Cheapest£564	Average£876	FlexibilityNo cancel fee	On-time77%	Search Iberia flights
Aer Lingus	Cheapest£592	Average£823	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
American Airlines	Cheapest£594	Average£933	FlexibilityNo cancel fee	On-time71%	Search American Airlines flights
JetBlue	Cheapest£742	Average£883	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 £239

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 15/2. 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 9 November 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 9 November 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 9 November 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 9 November 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 9 November 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 9 November 2026.

Last-minute flights from Illinois to HeathrowDiscover last-minute flight deals from Illinois to Heathrow. Data last updated 9 November 2026 and is based on user searches.

Discover last-minute flight deals from Illinois to Heathrow. Data last updated 9 November 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 9 November 2026.

Search for one-way flight options from Illinois to Heathrow. Find affordable one-way fares based on user searches. Data last updated 9 November 2026.

Find flight deals from Illinois to Heathrow

Round-trip from

One-way from

Popular in

Cheapest in

Average price

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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 9 November 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.

Weekly flight availability from Illinois to London Heathrow Airport

Explore weekly flight availability from Illinois to Heathrow. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 9 November 2026.

The most flights from USIL to LHR are scheduled on a Friday (45 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (38 on average).

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

Airfare is below average for this route at the moment.

Illinois to London Heathrow Airport flights typically cost between £547 and £869 in January.The cheapest return price found within the last 5 days was £486 on Multiple Airlines (12 Jan–20 Jan).

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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Search flights from Illinois to Heathrow by cabin class

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Other flights to Heathrow

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Top 7 airlines flying from Illinois to Heathrow

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

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

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 9 November 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 9 November 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 9 November 2026.

Last-minute flights from Illinois to Heathrow
Discover last-minute flight deals from Illinois to Heathrow. Data last updated 9 November 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 9 November 2026.

Illinois to London Heathrow Airport flights typically cost between £547 and £869 in January.
The cheapest return price found within the last 5 days was £486 on Multiple Airlines (12 Jan–20 Jan).