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Cheap flights from the United Kingdom to Illinois from £243
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 22/10. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ORD
3 Sep — 10 Sep1
Return
1 adult
Economy
Cheap flight deals from United Kingdom to Illinois
Keep the following information in mind while searching for United Kingdom to Illinois flight deals. Data was last updated 29 August 2025.
Find flight deals from United Kingdom to Illinois
Cheapest flights from United Kingdom to IllinoisExplore the most affordable flight options available from United Kingdom to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 August 2025.
Explore the most affordable flight options available from United Kingdom to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 29 August 2025.
Thu 25/908:45LCY - ORD
2 stops20h 30mMultiple Airlines
Sat 4/1017:55ORD - LCY
2 stops17h 20mMultiple Airlines
Deal found 28/8£420
Sat 6/907:25LHR - ORD
1 stop12h 40mUnited Airlines
Mon 15/913:12ORD - LHR
1 stop10h 43mUnited Airlines
Deal found 27/8£420
Wed 17/914:00LGW - ORD
1 stop32h 12mMultiple Airlines
Wed 1/1007:20ORD - LGW
2 stops20h 40mMultiple Airlines
Deal found 28/8£420
Wed 29/1009:25LCY - ORD
1 stop12h 55mSWISS
Wed 5/1118:50ORD - LCY
1 stop12h 00mSWISS
Deal found 28/8£420
Thu 11/907:40LHR - ORD
1 stop14h 05mAmerican Airlines
Mon 15/920:40ORD - LHR
Nonstop7h 50mAmerican Airlines
Deal found 28/8£420
Sun 14/914:00LGW - MDW
2 stops23h 11mMultiple Airlines
Mon 6/1008:15MDW - LGW
2 stops19h 45mMultiple Airlines
Deal found 27/8£421
Sat 30/810:00LGW - ORD
2 stops19h 33mMultiple Airlines
Sun 5/1020:49ORD - LGW
1 stop31h 11mMultiple Airlines
Deal found 26/8£421
Thu 4/907:40LHR - ORD
1 stop14h 05mAmerican Airlines
Mon 15/917:40ORD - LHR
Nonstop7h 40mAmerican Airlines
Deal found 27/8£421
Sat 6/908:50LGW - ORD
1 stop16h 10mMultiple Airlines
Mon 15/921:15ORD - LGW
1 stop15h 20mMultiple Airlines
Deal found 28/8£422
Sun 7/907:30LHR - ORD
1 stop13h 25mUnited Airlines
Sat 27/916:00ORD - LHR
Nonstop8h 20mUnited Airlines
Deal found 27/8£422
Sat 22/1106:30LHR - MDW
2 stops17h 48mVirgin Atlantic
Sat 6/1210:35MDW - LHR
1 stop15h 15mVirgin Atlantic
Deal found 27/8£422
Fri 5/910:00LGW - MDW
2 stops19h 20mMultiple Airlines
Mon 29/908:19MDW - LGW
1 stop19h 41mMultiple Airlines
Deal found 27/8£423
Cheapflights Fare Finder
Customise your flight search to find flights from United Kingdom 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 29 August 2025.
Use the filters below to find and compare flights from the United Kingdom to Illinois that are best for you.
Fly from
United Kingdom
Fly to
Illinois
Route
Depart
Return
Price
LondonChicago
LCY - ORD
LCYORD
London City
Thu 25/9
08:45-23:15
2 stops20h 30m
Chicago O'Hare Intl
Sat 4/10
17:55-17:15
2 stops17h 20m
£420
LondonChicago
LHR - ORD
LHRORD
London Heathrow
Mon 8/9
06:00-13:20
1 stop13h 20m
Chicago O'Hare Intl
Wed 24/9
21:50-11:45
Nonstop7h 55m
£420
LondonChicago
LHR - ORD
LHRORD
London Heathrow
Sat 13/9
07:25-14:05
1 stop12h 40m
Chicago O'Hare Intl
Thu 18/9
18:00-08:20
Nonstop8h 20m
£420
LondonChicago
LHR - ORD
LHRORD
London Heathrow
Fri 7/11
06:35-14:10
1 stop13h 35m
Chicago O'Hare Intl
Fri 28/11
17:50-07:55
Nonstop8h 05m
£420
LondonChicago
LHR - ORD
LHRORD
London Heathrow
Sat 6/9
07:25-14:05
1 stop12h 40m
Chicago O'Hare Intl
Mon 15/9
13:12-05:55
1 stop10h 43m
£420
LondonChicago
LGW - ORD
LGWORD
London Gatwick
Wed 17/9
14:00-16:12
1 stop32h 12m
Chicago O'Hare Intl
Wed 1/10
07:20-10:00
2 stops20h 40m
£420
LondonChicago
LGW - ORD
LGWORD
London Gatwick
Mon 8/9
10:00-23:20
2 stops19h 20m
Chicago O'Hare Intl
Thu 25/9
10:27-07:00
1 stop14h 33m
£420
LondonChicago
LGW - ORD
LGWORD
London Gatwick
Tue 21/10
15:40-18:15
1 stop32h 35m
Chicago O'Hare Intl
Tue 28/10
19:30-10:55
1 stop10h 25m
£421
LondonChicago
LHR - ORD
LHRORD
London Heathrow
Mon 6/10
06:30-16:11
2 stops15h 41m
Chicago O'Hare Intl
Mon 13/10
20:38-13:10
1 stop10h 32m
£421
LondonChicago
LGW - MDW
LGWMDW
London Gatwick
Sun 14/9
14:00-07:11
2 stops23h 11m
Chicago Midway
Mon 6/10
08:15-10:00
2 stops19h 45m
£421
Showing 1-10 of 60 results
Best time to book a flight from United Kingdom to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from United Kingdom 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 the United Kingdom to Illinois
What is the cheapest month to book a flight from United Kingdom to Illinois?
Currently, January is the cheapest month in which you can book a flight from United Kingdom to Illinois (average of £595). Flying from United Kingdom 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 GB to IL?
Find hourly flight availability from United Kingdom 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 29 August 2025.
When flying from United Kingdom 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 United Kingdom to Illinois
Explore weekly flight availability from United Kingdom 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 29 August 2025.
The most flights from GB0 to USIL are scheduled on a Wednesday (53 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (39 on average).
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 29 August 2025.
Read through reviews of airlines operating flights from the United Kingdom to Illinois, such as Finnair, Aer Lingus, andIcelandair. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Boarding
7.6
Comfort
7.5
Overall
7.6
Crew
8.1
Food
6.7
Entertainment
6.9
Reviews
1 / 20
10.0
ExcellentAnonymous,May 2025
FRA - DFW
Related info for your journey
Find useful and relevant information for your journey from United Kingdom to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Browse thousands of different options on Cheapflights for your next trip
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Alternative routes for United Kingdom to Illinois
See prices for flight routes from nearby airports that may be better suited for you.
Top 10 airlines flying from United Kingdom to Illinois
Discover the top 10 airlines that operate flights from United Kingdom 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 29 August 2025.
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 United Kingdom to Illinois?
900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Illinois from United Kingdom today with Cheapflights!
Why should you use Cheapflights to find cheap flight tickets from United Kingdom to Illinois?
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 Illinois from United Kingdom.
Can Cheapflights find flights from United Kingdom to Illinois with no change fees?
Cheapflights does show flights with no change fees to all users. To see these options for flights from United Kingdom to Illinois, users can toggle the no change fees filter when performing a flight search.
Can Cheapflights notify me if prices for flights from United Kingdom to Illinois become cheaper?
Yes, Cheapflights offers price alerts on United Kingdom to Illinois 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.