£237 Find Cheap Flights from London to Illinois

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from London to Illinois departing on 22/1. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Illinois

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from London to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from London to Illinois.
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Cheap Flights from London to Illinois

Cheapest return prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago2 stops£449
Moline
Moline2 stops£800
Peoria
Peoria2 stops£825
Champaign
Champaign2 stops£815
Chicago
Chicago2 stops£449
Moline
Moline2 stops£800
Peoria
Peoria2 stops£825
Champaign
Champaign2 stops£815

Book Cheap London to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from London to Illinois that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from London to Illinois

Thu, 22 Jan - Mon, 26 Jan
Multiple Airlines Logo
14:00 - 23:33
LGW
-
STL
15h 33m1 stop
Multiple Airlines Logo
10:16 - 10:00
STL
-
LGW
17h 44m1 stop
£360Multiple Airlines
Fri, 30 Jan - Fri, 6 Feb
Multiple Airlines Logo
14:00 - 23:33
LGW
-
STL
15h 33m1 stop
Multiple Airlines Logo
11:18 - 10:00
STL
-
LGW
16h 42m1 stop
£381Multiple Airlines
Thu, 22 Jan - Mon, 26 Jan
Multiple Airlines Logo
14:00 - 06:51
LGW
-
STL
22h 51m2 stops
Multiple Airlines Logo
10:16 - 10:00
STL
-
LGW
17h 44m1 stop
£404Multiple Airlines
Fri, 30 Jan - Fri, 20 Feb
Icelandair Logo
11:55 - 17:20
LGW
-
ORD
11h 25m1 stop
Icelandair Logo
18:30 - 10:55
ORD
-
LGW
10h 25m1 stop
£456Icelandair
Sun, 12 Apr - Mon, 20 Apr
Icelandair Logo
15:40 - 18:15
LGW
-
ORD
32h 35m1 stop
Icelandair Logo
19:25 - 14:40
ORD
-
LGW
13h 15m1 stop
£459Icelandair
Mon, 16 Mar - Mon, 23 Mar
British Airways Logo
08:20 - 17:13
LHR
-
STL
13h 53m1 stop
British Airways Logo
18:57 - 12:00
STL
-
LHR
12h 03m1 stop
£528British Airways
Wed, 22 Apr - Wed, 6 May
British Airways Logo
16:25 - 19:30
LHR
-
STL
9h 05mdirect
British Airways Logo
14:19 - 07:10
STL
-
LHR
10h 51m1 stop
£535British Airways
Mon, 16 Mar - Mon, 23 Mar
Finnair Logo
10:15 - 21:26
LHR
-
STL
16h 11m2 stops
Finnair Logo
11:47 - 06:50
STL
-
LHR
14h 03m1 stop
£537Finnair
Wed, 22 Apr - Wed, 6 May
Finnair Logo
07:30 - 21:48
LHR
-
STL
20h 18m2 stops
Finnair Logo
18:29 - 10:30
STL
-
LHR
10h 01m1 stop
£540Finnair
Mon, 16 Mar - Mon, 23 Mar
Aer Lingus Logo
06:50 - 23:04
LCY
-
STL
21h 14m2 stops
Aer Lingus Logo
14:32 - 12:40
STL
-
LCY
17h 08m2 stops
£769Aer Lingus
Booking Insights

KAYAK's insights & trends for London to Illinois flights

Get data-powered insights and trends into flights from London to Illinois to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest London to Illinois flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Illinois from London found in the last 72 hours was to Chicago, at £481 return. The most popular route is from London Heathrow Airport (LHR) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was £481.

Can I save money by flying with a stopover from London to Illinois?

The average return price for all direct flights, flights with one stopover, and flights with two stopovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of £512, prices are generally cheapest when you fly direct.

What is the cheapest month to fly from London to Illinois?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from London to Illinois, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from London to Illinois is February, when tickets cost £430 (return) on average. On the other hand, the most expensive months are July and August, when the average cost of return tickets is £649 and £615 respectively.

What’s the cheapest day of the week to fly from London to Illinois?

The average price of all round-trip flights from London to Illinois clicked on KAYAK for each day over the last 12 months.

Your flight ticket price will generally be cheaper if you fly to Illinois on a Wednesday and more expensive on a Saturday. On your return trip to London, you should consider flying back on a Sunday, and avoid Saturdays for better deals.

How far in advance should I book a flight from London to Illinois?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from London to Illinois, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below-average price on a flight from London to Illinois, you should book around 2 weeks before departure, which saves you about 22% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Good to know - Cheap tickets from London to Illinois

Low seasonNovember
Cheapest flight£237
Best time to beat the crowds (17% less expensive on average)
Most popular time to fly (25% more expensive on average)
Flight from London Gatwick Airport to St. Louis

Flights from London to Illinois: the best tips from KAYAK users

Insights shared by verified travellers who flew the route from London to Illinois 
Verified travelerFlew with British Airways
LHR
-
ORD
Jun 2025
I wish I'd known that there were food and shopping opportunities at the B gate area. This was a lovely, NOT busy place to spend time. I'd have gone directly there if I'd known. Definitely a nice place to wait.
Verified travelerFlew with British Airways
LHR
-
ORD
Apr 2025
Make sure to allow ample time between connecting flights. I have to hoof it when I realized that TSA required bags to be picked up and rechecked.
MichaelFlew with British Airways
LHR
-
ORD
Apr 2025
Have a light luggage as much as you can. Boarding gate walk is not a joke.
Verified travelerFlew with British Airways
LHR
-
ORD
Jul 2024
Gate 10 is a train wreck because there are multiple gates distinguished by a letter following A10. If possible get there as quickly as possible to find the appropriate gate.
EmilyFlew with British Airways
LHR
-
ORD
Mar 2024
Bring as few liquids as possible or put them in checked bag. They are very strict at Heathrow about all of them fitting into one small ziplock bag

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from London to Illinois?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from London to Illinois.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from London to Illinois?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from London to Illinois is likely to change within 7 days, so travellers know whether to wait or book now.

  • What is the Hacker Fare option on flights from London to Illinois?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly from London to Illinois with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from London to Illinois?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from London to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Illinois?

    The cheapest time of day to fly to Illinois is generally at night, when retur flights cost £558 on average. Morning departures are around 4% cheaper than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the evening, which is peak travel time and where the average cost of a ticket is £666.

Reviews of the top 5 airlines flying from London to Illinois

 
See real verified KAYAK customer reviews for airlines flying from London to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from London to Illinois? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.6
FinnairOverall score based on 1337 reviews
6.7Food
7.6Boarding
6.9Entertainment
7.4Comfort
8.1Crew
Airline reviews

All reviews good because...flight from BWI to London ,economy seats was miserable. I usually book 1,step up from economy but this would have added 1500 bucks 1 way. Bit the bullet and upgraded for retun flight, otherwise all ratings would have been rock bottom.

8.0 ExcellentDavid, Oct 2025
LHR - BWI
Read more Finnair reviews

All reviews good because...flight from BWI to London ,economy seats was miserable. I usually book 1,step up from economy but this would have added 1500 bucks 1 way. Bit the bullet and upgraded for retun flight, otherwise all ratings would have been rock bottom.

Great. It was awesome to have boarding from the front and back of the plane as it made the process go very quickly

It was okay. The airplane was a little smaller than a flight from Thailand to Helsinki.

Wish that everyone would board the back of the plane first. Also let kids on first. The gate wasn’t open at arrival and we waited 45 minutes to takeoff. They made up for time in the air.

This was an absolutely exceptional flight. The flight attendants were extremely attentive and very friendly. They seemed to go out of their way to make us comfortable and to make sure that we had everything we needed., We were in business and were very happy with the size and the details for our pods. We would definitely recommend Finnair and will definitely be flying with them again.

We had an excellent trip with Finnair. This was our first time and we’re very pleased. The only issue was with the boarding - it was a little bit confusing and needs a little bit of streamlining.

Crew very lovely. Arrived an hour late due to bad weather. We were given new tickets to an other flight but it could have been organised better, so we did not have to run through the whole airport to.

Major problems checking in at Alaska counter. They could not find our booking code because it came from Finnair.

Do not use KAYAK or Finair for future travel. Unless you purchase the tickets directly from the airline, you were going to have a difficult time checking in. Kayak canceled my flights twice and ended up causing great difficulty in me getting back from Europe because they double sold my tickets between American Airlines and Finair. The event caused significant delays and led to me having to rebook my flights.

The staff were all particularly great. The plane was clean and fresh. The bassinet worked great. It was all very nice.

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

Staff on board was excellent. Positive upbeat helpful- like it used to be.

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Very bad! They kept delaying my flight and wouldn’t do anything about it

Door to door, the crew and staff were amazing. It was a stressful travel day with delays, but they were focused on customers and doing what they could to get us to our destinations.

United has come a long way, it’s been a fantastic experience traveling with them.

This flight leg was fantastic - super comfortable and a great selection of things to watch on the TV. Staff were excellent, really above and beyond.

The flight attendants were very rude, beyond comprehension. I took a business class from London to SFO for the first time on United. When I asked for a second piece of bread during dinner, the serving attendant threw a 3rd bread on my plate and said, “here. You can have this one too”! I couldn’t believe the rudeness of the attendant. Most all attendants were very rude, unhelpful, sing the food was absolutely disgusting. Never fly United internationally in business class. My flight back to SFO was a nightmare!!

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Another delayed flight. When the delays exceed the duration of the flight, it’s a problem.

Food - Non-Existent. You pay for everything. It is strictly Pay-to-Play!

The Experience Was Torture Spend a few extra dollars and avoid Icelandair at all costs. There is absolutely no refreshments, no food, no drinks. Only water, coffee, tea are free and at only half a tiny cup. Entertainment is limited selection of films, shows and mostly outdated. The seats are smaller than usual, with no cushion, no pillows, no blankets. First time in my life have I witness an airline asking for donations in spare change for a charity. With all the money Icelandair saves by starving the passenger, they can afford to give this charity on their own.

Again, we paid $ 328.00 for specific seats are were assigned those seats.

Having been prepared for paying for everything on board other than water, coffee and tea the service was OK. Food and drink is expensive but the food was OK if limited in scope. Plane was clean and obviously well serviced. After complaining about having to walk in wind and rain to a get a bus to the airport the same thing happened at Portland. I’m sure you could get a terminal gate flight, complimentary food and drink for not much more money without traipsing through rain and slush in Reykjavik. Not bad but not great.

If there was a disclaimer regarding food service or lack thereof, l missed it. If l had known l would have prepared better. Same with transferring at Reykjavik. No information about disembarking via stairs into rain, slush and puddles deep enough to swallow a foot. After being treated to haute cuisine restaurants and warm inviting environment during the flight, the airport is, let’s be kind, disappointing. Plane was comfortable, Airbus, staff were welcoming enough. I would likely try the route again. Maybe have a night and day in Iceland. Maybe not.

The boarding process seem to take longer than necessary, resulting in a 20+ minute delay

It was too cold in the plane my feet froze

Handling our luggage was the biggest issue - they lost it and we got it almost 3 days later. Really threw off the beginning of our trip and we really had to change our itinerary accordingly.

Seat was hard and uncomfortable and the temperature too warm and uncomfortable.

No meals included on this long international flight. Most airlines will offer you a meal when flying internationally. Not Icelandair. Your included choices are water and coffee. Poor customer service. The airport was also very confusing.

Paid for exit row at the back of the plane. Window seat with lots of leg space. Food was inedible (as usual). Brought my own.

The seat space seemed small especially when the person ahead reclined but other than that, very good.

Luggage transfer in Chicago was not performed in time. I received my luggage at my destination two days later.

Food was poor quality and the screens for entertainment didn’t work properly

It was a short flight, everything was good with it.

I darted through the Frankfurt airport to make my connecting flight. I asked if it was a possibility to upgrade and the agent did. This was the kindest gesture and it made up for the previous delayed flight and distress/anxiety of anticipating that Zi was going to miss my Frankfurt-Chicago connection. I cannot express my gratitude for the upgrade.. I am 5feet 10 inches do the leg space was amazing.

I meant this flight was not good, the one from Tirana to Frankfurt was better!

I was very grateful for Lufthansa's role in organizing mobility support. The touchscreen on my seat was faulty: slow, stained (I couldn't get it clean), and glitchy. This made selecting movies extremely time consuming, and twice I had to start all over from the beginning.

The crew was the best I’ve ever encountered. Business class was spacious, immaculate, and very modern.

The flight was delayed by an hour. Made the connection uncomfortably tight.

I was in a bulkhead seat and my tray table wasn't level. Eating was difficult.

Audi visual not working for a whole group of seats in first class. How does a plane leave the main hub in such poor condition? How much that we can’t see so immediately is also compromised?

main meals are horrible but then you dont fly for the food

It was good. Couldn’t Check in online and select seats

It was great. Enough space and room for legs . Great service to.

⭐ British Airways Review — A Journey of Highs, Lows, and Lessons ⭐ I recently flew Business Class round-trip from Boston to Mumbai with British Airways, and my experience was a tale of two extremes — from disappointment to exceptional service, and then back to inconsistency. Boston → London: A Surprisingly Poor Start My journey began on a disappointing note. On a 6-hour Business Class flight, I was surprised to discover that there wasn’t a single proper vegetarian meal option available. I was offered a few bakery items only after repeatedly requesting something to eat. The flight attendant shrugged, offered no solution, and eventually — quite literally — threw some bread at me after much delay. This was not only disheartening, it was extremely surprising given my wonderful Business Class experience with BA last year. I stepped off that flight genuinely hungry and had to make a mad dash to the lounge just to get a proper meal. London → Mumbai: A Complete Turnaround The next sector restored my faith in British Airways. The entire crew was warm, welcoming, attentive, and genuinely caring. A special shoutout to Phiroze and the entire team serving the Business Class cabin — their professionalism, hospitality, and thoughtful service were extraordinary. They truly embodied what makes British Airways a global leader, and I am deeply grateful for the experience they provided. This is the BA I know and love. Mumbai → London: A Strange Meal Schedule This sector was generally fine, but the meal timing was puzzling. Lunch at 10:30 AM — for a Business cabin — felt unusual, and most passengers, including myself, barely touched it. The rest of the service was smooth, but the scheduling definitely needs a rethink. London → Boston: Mixed Experience Again The flight itself was decent, but the Business Lounge at Heathrow for this leg was a letdown. Arrived during lunch hours: no hot vegetarian options available Lounge area: dirty dishes everywhere Even after politely alerting the staff, the dishes were ignored and left uncleared For a premium cabin passenger — and at one of the world’s busiest international hubs — this was disappointing. Overall Impression My journey with British Airways felt inconsistent — two great sectors sandwiched between two that fell short of the BA standard. When BA is good, it is world-class. When it misses, the gap is noticeable. I genuinely hope the airline takes this feedback as constructive insight. I continue to believe in British Airways, and I commend the outstanding crew on the London → Mumbai sector — they were the highlight of my entire trip. With a little more focus on vegetarian meal availability, lounge service, and consistency across crews, BA can ensure every Business Class passenger experiences the premium journey they promise.

We were in business class and I had seat # 1. This was a night flight and after dinner was served, lights were dimmed and I went to sleep. The crew were loud and noisy so I didn’t get much sleep. I expect the crew to enjoy themselves but would Appreciate some decency in staying quiet while the passengers sleep

Have travelled business class with other airlines who profess to be the best in the world. They can however not beat the service and comfort that BA provide.

Great on board entertainment Tasty food Cattle class obviously crammed but not as bad as shorter hall flights

Logan gate staff was unhelpful. Arrived early, come to find out the airbus scheduled was reassigned and I did not have a seat. The desk agent spoke to his supervisor who instructed him to give me a boarding pass to get up to gate area, he was polite. At the gate the fellow was sitting to the side with two other BA staff . I asked him if he could help me, his answer was” we are on a break, we are closed” then turned his back. I am almost 70, drove 4 1/2 hours to Boston and had been looking forward to this trip for 5 months. I have worked in service many times in my life and this is not how it is done. I eventually (1/2 hr) before boarding was able to get a seat. The rest of the flight experience was unremarkable.

Everything you need to know for your flight from London to Illinois

Cabin class types available on flights to Illinois

Cabin classes available on flights to Illinois. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.