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Cheap flights from Illinois to London Heathrow Airport from £289

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 21/7. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — LHR
12 May — 19 May1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Illinois to Heathrow

Enter your travel dates to find the best prices.

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 12 April 2026.

Tue 21/420:10
ORD
-
LHR
1 stop18h 55m
Turkish Airlines
Wed 6/522:40
LHR
-
ORD
1 stop17h 00m
Turkish Airlines
Deal found 7/4£491
Tue 21/420:10
ORD
-
LHR
1 stop31h 40m
Turkish Airlines
Wed 29/411:20
LHR
-
ORD
1 stop28h 20m
Turkish Airlines
Deal found 8/4£492
Tue 14/420:10
ORD
-
LHR
1 stop18h 55m
Turkish Airlines
Thu 23/418:00
LHR
-
ORD
1 stop21h 40m
Turkish Airlines
Deal found 7/4£493
Sun 19/420:10
ORD
-
LHR
1 stop18h 55m
Turkish Airlines
Thu 14/516:45
LHR
-
ORD
1 stop22h 55m
Turkish Airlines
Deal found 9/4£494
Mon 26/1020:20
ORD
-
LHR
1 stop16h 20m
Scandinavian Airlines
Fri 6/1106:40
LHR
-
ORD
1 stop16h 05m
Scandinavian Airlines
Deal found 11/4£495
Wed 22/411:25
ORD
-
LHR
1 stop22h 35m
Turkish Airlines
Tue 5/506:30
LHR
-
ORD
1 stop33h 10m
Turkish Airlines
Deal found 7/4£498
Tue 14/420:10
ORD
-
LHR
1 stop20h 15m
Turkish Airlines
Tue 21/422:40
LHR
-
ORD
1 stop17h 00m
Turkish Airlines
Deal found 7/4£501
Sat 24/1020:20
ORD
-
LHR
1 stop14h 40m
Scandinavian Airlines
Sat 7/1110:20
LHR
-
ORD
1 stop12h 25m
Scandinavian Airlines
Deal found 11/4£503
Thu 5/1119:20
ORD
-
LHR
2 stops35h 35m
Scandinavian Airlines
Sun 8/1110:20
LHR
-
ORD
1 stop12h 25m
Scandinavian Airlines
Deal found 10/4£507
Wed 22/411:25
ORD
-
LHR
1 stop16h 25m
Turkish Airlines
Tue 28/422:40
LHR
-
ORD
1 stop17h 00m
Turkish Airlines
Deal found 7/4£507
Sun 6/913:30
STL
-
LHR
2 stops26h 10m
Scandinavian Airlines
Sat 12/906:40
LHR
-
STL
2 stops22h 57m
Scandinavian Airlines
Deal found 8/4£611
Mon 5/1015:42
STL
-
LHR
2 stops18h 18m
Scandinavian Airlines
Tue 13/1006:40
LHR
-
STL
2 stops22h 59m
Scandinavian Airlines
Deal found 10/4£613

Find flight deals from Illinois to Heathrow

Keep the following information in mind while searching for Illinois to Heathrow flight deals. Data was last updated 12 April 2026.

Round-trip from

£493

One-way from

£289

Popular in

June

Cheapest in

February

Average price

£517

Good round-trip deal

£623 or less

Good one-way deal

£360 or less
Turkish Airlines
  • Turkish Airlines
  • 27/4-6/5
  • 2 total stops
  • 51h 35m total
  • Illinois to London
Search Deals
Delta
  • Delta
  • 21/7
  • 2 total stops
  • 17h 58m total
  • Illinois to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (£121 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£22 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 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

 
Customise your flight search to find flights from Illinois to Heathrow 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, Cheapflights users made 858,174 searches. Data last updated 12 April 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

Cheapest return flight

ChicagoLondon

MDW - LHR

MDWLHR

Chicago Midway

Tue 28/4

12:52-13:15

1 stop18h 23m

London Heathrow

Wed 13/5

09:55-18:33

2 stops14h 38m

£648

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 18/8

12:10-06:30

1 stop12h 20m

London Heathrow

Tue 25/8

06:50-15:38

2 stops14h 48m

£648

PeoriaLondon

PIA - LHR

PIALHR

Greater Peoria

Tue 5/5

14:50-09:00

1 stop12h 10m

London Heathrow

Tue 12/5

06:50-16:50

2 stops16h 00m

£649

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Tue 29/9

16:25-06:45

Nonstop8h 20m

London Heathrow

Thu 8/10

14:05-20:12

1 stop12h 07m

£661

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 26/4

10:00-09:00

1 stop17h 00m

London Heathrow

Thu 7/5

14:05-20:25

1 stop12h 20m

£666

MolineLondon

MLI - LHR

MLILHR

Moline Quad-City

Thu 6/8

11:33-06:50

1 stop13h 17m

London Heathrow

Sat 22/8

12:55-23:25

1 stop16h 30m

£669

PeoriaLondon

PIA - LHR

PIALHR

Greater Peoria

Wed 12/8

12:20-10:55

1 stop16h 35m

London Heathrow

Wed 19/8

12:55-23:20

1 stop16h 25m

£670

BloomingtonLondon

BMI - LHR

BMILHR

Bloomington-Normal

Sun 23/8

06:00-06:50

1 stop18h 50m

London Heathrow

Tue 15/9

13:10-22:59

1 stop15h 49m

£671

ChicagoLondon

ORD - LHR

ORDLHR

Chicago O'Hare Intl

Fri 14/8

16:30-06:45

Nonstop8h 15m

London Heathrow

Fri 21/8

07:25-14:00

1 stop12h 35m

£674

MolineLondon

MLI - LHR

MLILHR

Moline Quad-City

Wed 23/9

08:25-05:55

2 stops15h 30m

London Heathrow

Wed 30/9

08:00-17:51

1 stop15h 51m

£674

Flights are sorted by cheapest return flights first.

Deals found on 7/4

Showing 1-10 of 60 resultsSorted by cheapest first
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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.
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

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

Currently, May is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £290). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £657). 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?

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 12 April 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 12 April 2026.

The most flights from USIL to LHR are scheduled on a Friday (52 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (42 on average).

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

Related info for your journey

Find useful and relevant information for your journey from Illinois to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

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

    For as low as £681, Virgin Atlantic can have you in London Heathrow Airport from Illinois in 10h 10m. 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 TAP AIR PORTUGAL, with whom users have recently found tickets for as low as £164. 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 Aer Lingus (83%), Air Canada (83%) or Austrian Airlines (83%) 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 £568 for a flight from Illinois to London Heathrow Airport. The cheapest flight overall is £303 while the most popular route, (Chicago O'Hare Intl - London Heathrow) is currently priced at £512.

  • 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, May is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £290). Flying from Illinois to London Heathrow Airport in June is currently the most expensive (average of £657). 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.

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Wembley
Croydon
Northampton
Hounslow
Gatwick
Luton
Ilford
Slough
Hayes
Brentford
Colchester
Watford
Kingston upon Thames
Romford
Eastbourne
Swindon
Chelmsford
Ipswich
Southend-on-Sea

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Alternative routes for Illinois to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Illinois to Heathrow

Discover the top 7 airlines that operate flights from Illinois to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 12 April 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest£357Average£513FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
American AirlinesCheapest£385Average£592FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
FinnairCheapest£413Average£574FlexibilityNo cancel feeOn-time76%
Search Finnair flights
British AirwaysCheapest£422Average£614FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Aer LingusCheapest£448Average£589FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
United AirlinesCheapest£461Average£662FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
IberiaCheapest£496Average£622FlexibilityNo cancel feeOn-time77%
Search Iberia flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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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