£253 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 23/2. 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.
Travellers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 25% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flight Deals
Booking Insights
Flight Deals

Cheap Flights from London to Illinois

Cheapest return prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago1 stop£384
Moline
Moline2 stops£696
Peoria
Peoria2 stops£696
Champaign
Champaign1 stop£738
Chicago
Chicago1 stop£384
Moline
Moline2 stops£696
Peoria
Peoria2 stops£696
Champaign
Champaign1 stop£738

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, 5 Mar - Sat, 14 Mar
Multiple Airlines Logo
14:00 - 09:06
LGW
-
ORD
25h 06m
1 stop
Multiple Airlines Logo
18:16 - 20:40
ORD
-
LGW
21h 24m
2 stops
£384Multiple Airlines
Thu, 19 Feb - Mon, 23 Feb
Icelandair Logo
12:15 - 17:20
LHR
-
ORD
11h 05m
1 stop
Icelandair Logo
18:30 - 10:50
ORD
-
LHR
10h 20m
1 stop
£384Icelandair
Wed, 18 Mar - Mon, 23 Mar
Multiple Airlines Logo
13:00 - 13:02
LGW
-
MDW
29h 02m
1 stop
Multiple Airlines Logo
21:51 - 10:00
MDW
-
LGW
31h 09m
1 stop
£385Multiple Airlines
Mon, 9 Feb - Wed, 29 Apr
British Airways Logo
08:50 - 20:04
LHR
-
ORD
17h 14m
2 stops
British Airways Logo
16:16 - 10:35
ORD
-
LHR
12h 19m
1 stop
£389British Airways
Sun, 1 Mar - Mon, 9 Mar
Lufthansa Logo
06:30 - 13:55
LHR
-
STL
13h 25m
1 stop
Lufthansa Logo
17:41 - 10:25
STL
-
LHR
11h 44m
1 stop
£422Lufthansa
Fri, 15 May - Sun, 17 May
British Airways Logo
06:45 - 14:00
LCY
-
ORD
13h 15m
1 stop
British Airways Logo
15:45 - 10:20
ORD
-
LCY
12h 35m
1 stop
£435British Airways
Sun, 1 Mar - Mon, 9 Mar
Lufthansa Logo
06:30 - 13:55
LHR
-
STL
13h 25m
1 stop
Lufthansa Logo
19:00 - 15:50
STL
-
LHR
15h 50m
2 stops
£437Lufthansa
Tue, 24 Feb - Tue, 3 Mar
United Airlines Logo
09:00 - 19:14
LHR
-
STL
16h 14m
2 stops
United Airlines Logo
09:55 - 06:40
STL
-
LHR
14h 45m
2 stops
£440United Airlines
Sun, 1 Mar - Mon, 9 Mar
United Airlines Logo
06:30 - 19:14
LHR
-
STL
18h 44m
2 stops
United Airlines Logo
11:25 - 06:40
STL
-
LHR
14h 15m
2 stops
£445United Airlines
Sun, 1 Mar - Sun, 15 Mar
Aer Lingus Logo
13:15 - 23:48
LCY
-
STL
40h 33m
2 stops
Aer Lingus Logo
06:13 - 08:35
STL
-
LCY
21h 22m
2 stops
£947Aer 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 £396 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 £396.

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 £533, 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 £420 (return) on average. On the other hand, the most expensive months are July and August, when the average cost of return tickets is £632 and £601 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 24% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Good to know - Cheap tickets from London to Illinois

Low seasonJanuary
Cheapest flight£253
Best time to beat the crowds (9% less expensive on average)
Most popular time to fly (26% 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 in the afternoon, when retur flights cost £620 on average. Morning departures are around 5% 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 £653.

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 1356 reviews
6.9Entertainment
6.7Food
7.7Boarding
7.5Comfort
8.2Crew
Airline reviews

It was a good flight, very comfortable seats for sleeping in business class. Probably the most comfortable business class seat I've ever had (20+ times in business class on various airlines). Service was good, but the only downside is my screen didn't work and it had to be reset multiple times to get it to shut off. I had to block my eyes because the screen was white almost the entire flight and I wore an eye mask when I slept. But when eating and reading in my seat, my eyes hurt because the only way to turn the screen off was reset it and the screen would only be off for a few minutes at a time.

8.0 ExcellentSunny, Jan 2026
LAX - HEL
Read more Finnair reviews

It was a good flight, very comfortable seats for sleeping in business class. Probably the most comfortable business class seat I've ever had (20+ times in business class on various airlines). Service was good, but the only downside is my screen didn't work and it had to be reset multiple times to get it to shut off. I had to block my eyes because the screen was white almost the entire flight and I wore an eye mask when I slept. But when eating and reading in my seat, my eyes hurt because the only way to turn the screen off was reset it and the screen would only be off for a few minutes at a time.

Everything was wonderful! AirBus seats are more comfortable to sleep in as compared to the Boeing planes.

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.

Flight delayed over an hour. They said they would hold our connection but then did not.

This Japanese airline provides great service and very helpful in assisting their passengers.

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

I so appreciate the crew members on each flight of United. They are outstanding.

Reliable, nice crew, I fly often on that flight and I like it all.

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

Everything was absolutely wonderful from check in to baggage claim. Staff was very professional and sweet. Will definitely recommend United to family and friends.

The staff was nice, however boarding taking 2 hours. That’s insane. Overall very bad experience, a lot of turbulence and when landed in Chicago was horrible. I don’t think I’ll flight with UA again.

An international flight on an apron is pretty unusual in my 40 years of traveling. Departure delay. Luggage despite over an hour connection did not make it to the flight. Actually still in Germany. My luggage was not moved until I reached my final destination despite knowing it to be left in Germany upon my arrival in Chicago. The service left me a little off, both going and returning from Europe. Light on in the cabin even during a night flight and lots of traffic no matter what. Maybe passengers want more service? As a frequent traveler i just want to be able to sleep, the food will be better at the destination anyway. So since the cabin crew woke me up I asked for a cocktail, I did not get the best response although sitting in row 20 premium economy. I usually fly premium economy or business and my 2 flight to Europe in 2025 with United both had luggage delays and other minor issues. American flights to Australia, Canada and Europe went smoothly and Premium plus feels very much like business light. Is United Club becoming a waste and Silver/Gold levels another waste??

Overall satisfied and would fly with them again. They could improve the check-in efficiency at BOS, we got backed up because it seemed there were passengers requiring much more time for check in.

The customer service was unbeatable from the wheelchair assist team to the flight attendants. The pilot also did an excellent job managing the turbulence.

Delays at check-in, seemed like they were short ground staff at the time and some passengers needed extra processing.

Problems checking in both on the laptop and on the app. No free seating available at check-in as advertised - must pay for EVERY seat between $23 and $75. No way to cancel seat choice. App menus and site menus are not responsive, and some items are impossible to find. Crew and mobile assistance are friendly and helpful.

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

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.

They had a 4 hour delay and left my luggage in Iceland and it didn’t arrive in Portland until 11/1

Iceland air transfer was bad. They lost my luggage and I just received it 11/1

We were in premium economy seats that appeared to be locked in plae, No reclining. My aching back.

I don’t understand how they charge as much as they do for such a poor experience

I wish the plane had pod seating for business class. I had a window seat (8K) and I had to climb over the person sitting on the aisle when I needed to get up. Also there is no partition between the seats for privacy when sleeping. The Asian airlines have much nicer business class seating. Their seats are wider for better comfort when sleeping.

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!

My touch screen at my seat wasn't working, the films BA advertised on the website for this flight were not available, and the plane was a little dated, food was good and the staff were good, just let down by the aircraft facilities.

Did not like the seating configuration at all with 2+3+2 in business class. Lacking total privacy and comfort

Check-in experience, for business call please provide a premium experience

Lost my luggage, ran out of food choices in business class, ground crew was completely unapologetic.

Excellent. The crew and flight were great. Checking in was easy and everyone was very helpful.

Entertainment devices on A380 need to be fixed, the seats might do with updates.

Everything. Employees offered to help me because I had to use a cane.

Check-in and boarding were great. On flight staff were rude and disrespectful. Paid for extra room and found it incredibly cramped. Bathrooms kept in poor condition. Overall negative experience.

Great seat in premium economy, great food and drinks throughout lots of in flight entertainment. 1 hour 40 min delayed flying out , 2 1/2 hour wait at passport control in tampa

My seat cushion was poor. The cushion was compressed and was uncomfortable for such a long flight.

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.