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Cheap flights from London Heathrow Airport to Illinois from £343

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 26/2. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
10 Feb — 17 Feb1
1 adult

Cheap flight deals from Heathrow to Illinois

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) to Illinois (USIL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 5 February 2025.

Round-trip from

£424

One-way from

£343

Popular in

August

Cheapest in

February

Average price

£458

Good round-trip deal

£539 or less

Good one-way deal

£588 or less
Icelandair
  • Icelandair
  • 4/3-31/3
  • 2 total stops
  • 29h 55m total
  • London to Illinois
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26/2
  • 26/2
  • 3 total stops
  • 46h 20m total
  • London to Illinois
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£64 potential increase over avg. return price).
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Cheapest flight prices on average. 2% potential price decrease (£11 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 2025
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Price to beat on a round-trip flight from London Heathrow to Illinois.
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Price to beat on a one-way flight from London Heathrow to Illinois.
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Find flight deals from Heathrow to Illinois

Cheapest flights from Heathrow to Illinois
Explore the most affordable flight options available from Heathrow to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 5 February 2025.

Tue 4/312:15LHR - ORD
1 stop11h 05mIcelandair
Mon 31/319:30ORD - LHR
1 stop18h 50mIcelandair
Deal found 3/2£424
Wed 23/409:30LHR - ORD
1 stop14h 20mFinnair
Wed 30/417:50ORD - LHR
Nonstop7h 35mFinnair
Deal found 4/2£427
Tue 4/306:30LHR - ORD
2 stops17h 02mVirgin Atlantic
Tue 25/317:30ORD - LHR
1 stop12h 05mVirgin Atlantic
Deal found 4/2£428
Tue 4/314:10LHR - ORD
Nonstop8h 50mBritish Airways
Tue 11/319:30ORD - LHR
Nonstop7h 45mBritish Airways
Deal found 4/2£429
Mon 3/313:45LHR - ORD
1 stop32h 30mLufthansa
Sat 8/320:30ORD - LHR
1 stop30h 00mLufthansa
Deal found 4/2£431
Fri 7/206:00LHR - ORD
1 stop15h 30mTAP AIR PORTUGAL
Sun 16/220:25ORD - LHR
1 stop15h 05mTAP AIR PORTUGAL
Deal found 4/2£432
Tue 18/306:10LHR - ORD
1 stop14h 20mAmerican Airlines
Thu 27/313:49ORD - LHR
1 stop14h 36mAmerican Airlines
Deal found 4/2£440
Tue 4/312:20LHR - MDW
1 stop11h 51mKLM
Tue 11/314:55MDW - LHR
1 stop10h 55mKLM
Deal found 4/2£440
Wed 12/206:30LHR - ORD
1 stop14h 00mDelta
Mon 24/313:35ORD - LHR
1 stop13h 20mDelta
Deal found 4/2£441
Wed 23/411:05LHR - ORD
Nonstop8h 45mIberia
Tue 13/516:55ORD - LHR
Nonstop7h 55mIberia
Deal found 4/2£442
Wed 19/212:20LHR - MDW
1 stop11h 51mVirgin Atlantic
Mon 24/210:57MDW - LHR
1 stop13h 23mVirgin Atlantic
Deal found 4/2£442
Mon 24/208:40LHR - MDW
2 stops15h 31mDelta
Mon 10/314:55MDW - LHR
1 stop10h 55mDelta
Deal found 4/2£445

Find flights from Heathrow to Illinois within your budget

Customise your flight search to find flights from Heathrow to Illinois 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 5 February 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 4/3

12:15-17:20

1 stop11h 05m

Chicago O'Hare Intl

Mon 31/3

19:30-20:20

1 stop18h 50m

£424

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 23/4

09:30-17:50

1 stop14h 20m

Chicago O'Hare Intl

Wed 30/4

17:50-07:25

Nonstop7h 35m

£427

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 4/3

06:30-17:32

2 stops17h 02m

Chicago O'Hare Intl

Tue 25/3

17:30-10:35

1 stop12h 05m

£428

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 4/3

14:10-17:00

Nonstop8h 50m

Chicago O'Hare Intl

Tue 11/3

19:30-08:15

Nonstop7h 45m

£429

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 3/3

13:45-16:15

1 stop32h 30m

Chicago O'Hare Intl

Sat 8/3

20:30-08:30

1 stop30h 00m

£431

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 17/2

06:40-17:50

1 stop17h 10m

Chicago O'Hare Intl

Mon 3/3

19:40-18:50

2 stops17h 10m

£433

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Wed 19/2

06:00-15:30

1 stop15h 30m

Chicago O'Hare Intl

Sun 2/3

20:25-22:40

1 stop20h 15m

£434

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Tue 18/3

06:10-15:30

1 stop14h 20m

Chicago O'Hare Intl

Sun 23/3

16:40-12:00

1 stop14h 20m

£440

LondonChicago

LHR - MDW

LHRMDW

London Heathrow

Tue 4/3

12:20-18:11

1 stop11h 51m

Chicago Midway

Tue 11/3

14:55-06:50

1 stop10h 55m

£440

LondonChicago

LHR - ORD

LHRORD

London Heathrow

Mon 17/2

08:40-14:30

1 stop11h 50m

Chicago O'Hare Intl

Thu 20/3

08:25-06:55

1 stop17h 30m

£441

Flights are sorted by cheapest return flights first.

Deals found on 4/2

Showing 1-10 of 55 results
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Best time to book a flight from Heathrow to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Heathrow 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.

Travel insights for flights from Heathrow to Illinois

Get recent, data-driven insights about flights from Heathrow to Illinois including ideal travel times, pricing trends, and more.

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

Currently, January is the cheapest month in which you can book a flight from London Heathrow Airport to Illinois (average of £595). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £843). 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 LHR to IL?

Find hourly flight availability from Heathrow to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 5 February 2025.

When flying from London Heathrow Airport to Illinois, 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 London Heathrow Airport to Illinois

Explore weekly flight availability from Heathrow to Illinois. 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 5 February 2025.

The most flights from LHR to USIL are scheduled on a Monday (32 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (27 on average).

Rainfall in Illinois by month

Plan your trip to Illinois by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Illinois ranges from 43.0 - 125.0 inches per month. August is typically the wettest month, when rainfall can reach 125.0 mm. January is typically the driest time to visit Illinois when rainfall is around 43.0 mm.

Temperature in Illinois by month

Plan your trip to Illinois by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Illinois, 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 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -5.0 C).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated 5 February 2025.
Read reviews from past customers who have flown Delta, KLM and Finnair from London to Illinois. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Delta
8.0
Very Good
8,408 reviews
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

KLM
7.8
Good
1,334 reviews
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Finnair
7.6
Good
1,284 reviews
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Austrian Airlines
7.5
Good
785 reviews
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

SWISS
7.5
Good
1,582 reviews
Delta
8.0
Very Good
8,408 reviews
Check prices

Food

7.3

Entertainment

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Comfort

8.0

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Related info for your journey

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

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

    One-way options have recently been found by users for as low as £379 on Air Serbia. Other airlines that offer cheap prices include WestJet from £402 and Aer Lingus from £403 one-way.

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

    The most popular flight routes from London Heathrow Airport to Illinois are London Heathrow - Chicago O'Hare Intl, London Heathrow - Chicago Midway and London Heathrow - Lambert-St Louis.

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

    Before booking your flight to Illinois from London Heathrow Airport, check out the most reliable airlines to get you to your destination on time: Air Canada (93%), Austrian Airlines (93%), United Airlines( 93%).

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

    Looking at all options, your cheapest flight can be booked for £440. While the most popular route (London Heathrow - Chicago O'Hare Intl) can be booked for £376 on average our data indicates £1,191 when flying from London Heathrow Airport to Illinois.

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

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

  • How can I find direct flights from Heathrow to Illinois?

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

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

    Yes. Cheapflights offers flight deals from Heathrow to Illinois 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 London Heathrow Airport to Illinois?

    Currently, January is the cheapest month in which you can book a flight from London Heathrow Airport to Illinois (average of £595). Flying from London Heathrow Airport to Illinois in July is currently the most expensive (average of £843). 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

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Alternative routes for Heathrow to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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Gatwick to Las Vegas flights
Gatwick to Stewart flights
Gatwick to San Francisco flights
London City to Boston flights
London City to San Francisco flights
Heathrow to George Bush Intcntl flights
Gatwick to O'Hare Intl flights
Heathrow to Charlotte flights
London City to O'Hare Intl flights
Heathrow to Midway flights
Stansted to Newark flights

Top 10 airlines flying from Heathrow to Illinois

Discover the top 10 airlines that operate flights from Heathrow to Illinois. 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 5 February 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest£375Average£548FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
Scandinavian AirlinesCheapest£382Average£533FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
TAP AIR PORTUGALCheapest£394Average£589FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
Virgin AtlanticCheapest£416Average£624FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
LufthansaCheapest£446Average£599FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
United AirlinesCheapest£446Average£633FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
British AirwaysCheapest£450Average£728FlexibilityNo cancel feeOn-time70%
Search British Airways flights
Aer LingusCheapest£457Average£604FlexibilityNo cancel feeOn-timeN/A
Search Aer Lingus flights
Austrian AirlinesCheapest£471Average£611FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
FinnairCheapest£474Average£839FlexibilityNo cancel feeOn-time76%
Search Finnair 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 Heathrow to Illinois?

Cheapflights helps you search for flights from Heathrow to Illinois via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Heathrow to Illinois for you. Better yet — we are completely free to use.

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

Yes! Cheapflights helps users easily find flights from Heathrow to Illinois with no change fees.

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

Of course! You can now track prices for flights from Heathrow to Illinois and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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