Cheap flights from Illinois to London Heathrow Airport from £232
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 25/8. Fares are subject to change and may not be available on all flights or dates of travel.
Cheap flight deals from Illinois to Heathrow
Keep the following information in mind while searching for Illinois to Heathrow flight deals. Data was last updated 13 June 2025.
Find 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 13 June 2025.
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 13 June 2025.
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 13 June 2025.
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
MolineLondon
MLI - LHR
MLILHR
Moline Quad-City
Mon 11/8
18:33-10:55
1 stop10h 22m
London Heathrow
Tue 19/8
09:15-15:50
1 stop12h 35m
PeoriaLondon
PIA - LHR
PIALHR
Greater Peoria
Tue 19/8
18:39-10:30
1 stop9h 51m
London Heathrow
Tue 26/8
09:15-18:09
1 stop14h 54m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Tue 26/8
19:15-18:50
2 stops17h 35m
London Heathrow
Sat 6/9
10:20-16:10
1 stop11h 50m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Mon 4/8
15:14-07:50
1 stop10h 36m
London Heathrow
Wed 13/8
09:15-11:55
Nonstop8h 40m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Sun 20/7
16:05-06:20
Nonstop8h 15m
London Heathrow
Tue 29/7
14:10-17:20
Nonstop9h 10m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Sun 2/11
19:05-16:40
2 stops15h 35m
London Heathrow
Tue 11/11
06:00-16:15
1 stop16h 15m
ChicagoLondon
MDW - LHR
MDWLHR
Chicago Midway
Mon 4/8
10:30-13:30
1 stop21h 00m
London Heathrow
Wed 13/8
09:00-21:49
2 stops18h 49m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Mon 28/7
07:04-06:30
2 stops17h 26m
London Heathrow
Tue 12/8
09:30-09:52
1 stop30h 22m
ChicagoLondon
MDW - LHR
MDWLHR
Chicago Midway
Sun 27/7
18:47-13:30
1 stop12h 43m
London Heathrow
Tue 5/8
09:20-16:10
1 stop12h 50m
ChicagoLondon
ORD - LHR
ORDLHR
Chicago O'Hare Intl
Wed 10/9
16:55-06:50
Nonstop7h 55m
London Heathrow
Sat 27/9
06:15-15:45
1 stop15h 30m
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
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, January is the cheapest month in which you can book a flight from Illinois to London Heathrow Airport (average of £112). Flying from Illinois to London Heathrow Airport in August is currently the most expensive (average of £164). 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 13 June 2025.
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 13 June 2025.
The most flights from USIL to LHR are scheduled on a Monday (57 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (52 on average).
Rainfall in Heathrow by month
Plan your trip to Heathrow by taking into account the average rainfall totals by month.
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.
Temperature in Heathrow by month
Plan your trip to Heathrow by taking into account the average temperature totals by month.
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).
Reviews of airlines servicing Heathrow
Get insights into the airlines that provide service to Heathrow. 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 Heathrow. Reviews last updated 13 June 2025.
To help decide which airline to fly from Illinois to London, see what other customers have to say about Delta, KLM and Austrian Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
Boarding
Food
Crew
Comfort
Overall
Entertainment
Reviews
Kim,May 2025
PIH - SLC
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.
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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.
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 13 June 2025.
Fly with Cheapflights
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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.