£356 Find Cheap Flights from London Heathrow Airport 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 Heathrow to Illinois departing on 20/9. 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 Heathrow to Illinois

Cheapest return prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago1 stop£514
Moline
Moline1 stop£789
Peoria
Peoria1 stop£905
Springfield
Springfield2 stops£770
Bloomington
Bloomington2 stops£1,125
Chicago
Chicago1 stop£514
Moline
Moline1 stop£789
Peoria
Peoria1 stop£905
Springfield
Springfield2 stops£770
Bloomington
Bloomington2 stops£1,125

Book Cheap Heathrow to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Heathrow 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 Heathrow to Illinois

Wed, 7 Oct - Tue, 13 Oct
Icelandair Logo
13:05 - 18:15
LHR
-
ORD
11h 10m
1 stop
Icelandair Logo
19:25 - 11:55
ORD
-
LHR
10h 30m
1 stop
£514Icelandair
Sat, 13 Jun - Sat, 13 Jun
United Airlines Logo
08:00 - 11:05
LHR
-
ORD
9h 05mdirect
United Airlines Logo
15:40 - 06:30
ORD
-
LHR
32h 50m
1 stop
£517United Airlines
Fri, 10 Jul - Sat, 5 Sep
Icelandair Logo
13:05 - 18:15
LHR
-
ORD
11h 10m
1 stop
Icelandair Logo
19:25 - 11:55
ORD
-
LHR
10h 30m
1 stop
£518Icelandair
Tue, 1 Sep - Mon, 14 Sep
British Airways Logo
11:10 - 13:50
LHR
-
ORD
8h 40mdirect
British Airways Logo
19:05 - 09:05
ORD
-
LHR
8h 00mdirect
£528British Airways
Tue, 8 Sep - Tue, 22 Sep
Finnair Logo
16:10 - 23:20
LHR
-
STL
37h 10m
2 stops
Finnair Logo
12:43 - 09:05
STL
-
LHR
14h 22m
1 stop
£630Finnair
Tue, 15 Sep - Tue, 22 Sep
Finnair Logo
14:45 - 23:20
LHR
-
STL
14h 35m
1 stop
Finnair Logo
12:43 - 12:50
STL
-
LHR
18h 07m
1 stop
£634Finnair
Mon, 21 Sep - Thu, 5 Nov
American Airlines Logo
12:30 - 18:58
LHR
-
STL
12h 28m
1 stop
American Airlines Logo
14:17 - 06:55
STL
-
LHR
10h 38m
1 stop
£637American Airlines
Tue, 8 Sep - Tue, 22 Sep
British Airways Logo
16:25 - 19:30
LHR
-
STL
9h 05mdirect
British Airways Logo
12:47 - 06:55
STL
-
LHR
12h 08m
1 stop
£645British Airways
Fri, 28 Aug - Sat, 5 Sep
American Airlines Logo
13:15 - 00:09
LHR
-
SPI
16h 54m
2 stops
American Airlines Logo
14:52 - 09:05
SPI
-
LHR
12h 13m
1 stop
£850American Airlines
Mon, 15 Jun - Sat, 20 Jun
Lufthansa Logo
11:05 - 22:45
LHR
-
PIA
17h 40m
1 stop
Lufthansa Logo
17:33 - 11:55
PIA
-
LHR
12h 22m
1 stop
£3,927Lufthansa
Booking Insights

KAYAK's insights & trends for Heathrow to Illinois flights

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

How much is a return flight from London Heathrow Airport to Illinois?

This analysis is based on the cheapest return trip price found on KAYAK in the last 12 months by searching for a flight from London Heathrow Airport to Illinois departing in October.

What is the cheapest London Heathrow Airport 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 Heathrow Airport found in the last 72 hours was to Chicago, at £524 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 £524.

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

The average price for all round-trip flights from London Heathrow Airport to Illinois depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Illinois is generally in the afternoon, when retur flights cost £639 on average. Morning departures are around 2% 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 £665.

Can I save money by flying with a stopover from London Heathrow Airport 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 £669, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from London Heathrow Airport 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 Heathrow Airport to Illinois is February, when tickets cost £277 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of return tickets is £898 and £671 respectively.

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

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

If you are looking for a flight deal from London Heathrow Airport to Illinois, look for departures on Wednesdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Illinois, Sunday is the cheapest day to fly and Friday is the most expensive.

How far in advance should I book a flight from London Heathrow Airport 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 Heathrow Airport 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 Heathrow Airport 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 23 weeks before departure.

Good to know - Cheap tickets from London Heathrow Airport to Illinois

Low seasonJanuary
Cheapest flight£356
Best time to beat the crowds (2% less expensive on average)
Most popular time to fly (17% more expensive on average)
Flight from London Heathrow Airport to St. Louis

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

Insights shared by verified travellers who flew the route from Heathrow 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 Heathrow Airport 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 Heathrow Airport to Illinois.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from London Heathrow Airport 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 Heathrow Airport 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 Heathrow Airport 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 Heathrow Airport 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 Heathrow Airport to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines flying from Heathrow 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 Heathrow 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.
7.4
United AirlinesOverall score based on 9678 reviews
7.3Comfort
6.6Food
7.7Boarding
7.1Entertainment
8.1Crew
Airline reviews

Flight crew was super friendly and helpful. Food was frequent and honestly pretty good. Plenty of on-board entertainment. Economy seats are super cramped for such a long flight, but the crew allowed people to get up and stretch, and kids could wander with their parents, so we all made it work. Overall a very good experience.

8.0 ExcellentAnonymous, Apr 2026
ZRH - ORD
Read more United Airlines reviews

Flight crew was super friendly and helpful. Food was frequent and honestly pretty good. Plenty of on-board entertainment. Economy seats are super cramped for such a long flight, but the crew allowed people to get up and stretch, and kids could wander with their parents, so we all made it work. Overall a very good experience.

Standard flight with a drinks and a snack- overall very quick flight. The flight attendants were very strict, bordered on rude.

Starlink is great Crew was polite Business class didn’t get a welcome drink just water and snacks were ok

Delayed - weather wasn't bad at either end. Also sat on tarmac in ORD.

very average service no complimentary alcoholics drinks unlike other airlines such as Porter airlines No decent seats available during check-in time the day before

boarded early to only find out that flight would sit at gate for 45 min to an hour. Landed in chicago and sat on runway for over an hour before got to gate. Total delay was extensive for a 45 min flight door to door.

The flight was significantly delayed. The inbound flight from EWR was delayed departing because of mechanical problems. My original departure from CLT was 5:28 pm but due to the delay of the inbound flight, after arrival, deplaning, cleaning, boarding, we did not push back from the gate until 9:00 pm. Once in the air, the flight was smooth and what was originally supposed to be an arrival in ORD at 7:30 pm local time turned out to be 9:35 pm.

The flight I was supposed to be on was supposed to take off at 1:50 from State College. It was delayed over and over and over again until somehow I had to rebook on a flight that was supposed to have left State College at 8 am that morning but didn't end up taking off until almost 6 pm. Not only was this completely unacceptable, the "token from United" was a 15 dollar meal voucher that has to be used by today. I would personally like some miles added to my account for this inconvenience. I was in transit for 8 hours from the time I arrive at State College Aiport to when I got home. I was supposed to be home at 3 pm and I returned at 8 pm. Unacceptable. I have not been on an on Time united flight in nearly 5 years.

newer aircraft, ability to connect my headset via blue tooth for entertainment.

First time flying with UA and it was a great experience. Thank you

I sat in the first row behind first class. There was plenty of legroom. The entertainment was great. I saw two excellent movies and one episode of a sitcom. Also enjoyed the flight tracker.

OK overall. Flight was delayed Crew on flight was good

On time, only a little turbulence, very competent and caring attendants. Clear information.

Late late late. Delayed and arrived an hour late for a 1 hour 45 minute connection. Every time. Poor record for this company. I try to fly any other carrier first.

The flights are literally always delayed arriving, boarding and taking off so they are always late for the connection. I planned ahead so I was okay but many others aren't. The food was terrible. The staff was very pleasant. I appreciate boarding back to front.

The crew was friendly. The plane was comfortable. In-flight wifi didn't work well at all. The ride was quite turbulent but understandable given the weather.

My issue is with the SkyWest terminal. The flight was not listed on the main airport flight screen list, and I had to do a Google search to locate the terminal and gate. We had to ask several airport employees where to locate the phantom gate. The airport did not provide adequate signage and was confusing. When we arrived, there was one vendor providing services that quickly closed, leaving zero options for food and drink while we waited hours for our delayed flight. The crew that assisted with check-in and boarding was VERY friendly.

Economy seats a bit small but other than that it was all good.

delayed flight stayed whole night at washington Dallas airport at seats , uncomfortable . i am senior citizen , very tired , worst travel.

No complimentary drinks or snacks offered on a 2 hour flight was disappointing but everything else went well

The Icelandair crew was so kind!!! Thank you for making my first trip to Paris a great one!

I am not going to fillo this out for each leg of my trip. My first review holds for the experience

The movie choices were poor. The worst problem is the treatment of passengers durinng pre-boarding. In one case the primes were checked in and sent down the boarding tunnek only to stand waiting there while the plane is cleaned. In the second case the bus was loaded, the doors closed and just stood there unmoving like sardeines in a tin for over TEN minutes. In both cases it was rough on us old guys who find standing for long periods trying.. In other words, Donnt just stack us up and forget us.

I had no idea that my ticket only paid for my right to get on the plane. They charged me $130 for my carry-on bag because it was 1 inch too big she claimed but it wasn’t! Then they wanted another fee for everything. I had no idea that Icelandair had changed to such a bargain basement airline. I was very disappointed.

Screen didn't work, and neither did the button to tilt the seat even though the seat was comfortable

The most uncomfortable seat i’ve ever had on a flight

Waiting area on top of stairs before Boarding the bus wasn’t great. Took a long time to load the bus to gate.

The real reason why the flying experience with Icelandair ---was mediocre was because of not being able to enter DC airspace yesterday evening. This obviously was out of your control and do realize this is a safety issue. I did notice---that everything was being done to get us to Washington Dulles and we did arrive at Dulles SAFELY with just a 4 hour delay. Thank you!

They wouldn’t check in my luggage even though I had one checked bag prepaid. So I took my bag to the gate and tried to check it in there and two employees scolded me for bringing a large bag to the gate. I told them I was trying to check it in and that it was prepaid, and they said they couldn’t guarantee that it would arrive at my destination but they finally let me drop it off when boarding the plane and pick it up right after exiting the plane. There was no food, and there was no entertainment.

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.

Everything could have been better. What needed to be wrong with United went wrong

It was good. The seats in economy weren’t bad

Flight map did not work. Crew was great, food was good, plane took off on time and landed early. That's all I can ask.

Very good. Comfortable and I felt well taken care of from start to finish

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.

A shout-out to the flight attendent, Lauren, who was the main person assisting me. She was amazing - perfect balance of bright, cheerful, engaging, yet formal

OK, except for a cabin attendant's lack of attention.

efficient. on time. cabin crew were very professional and very nice to deal with. would definately fly BA again.

It was great overall. A few slight improvements could be made on the onboarding process at the Gates with announcements and clarity of communications (both at the gate and in flight). The movies in the entertainment options could be improved for bollywood, hollywood.

I alrady responded to this request, and expllaned at length that this was the worst flying experience in my 77 years. I will NEVER fly BA again.

Airbus A350 is poorly designed for wheelchair users and reduced mobility passengers. The angle of the pods makes it awkward to transfer. I was able to but I have ab stability. It could be a real challenge for people with more severe mobility impairments. You'd think Airbus would have come up with a solution for this or thought more about us disabled folks more when designing this aircraft.

The crew has always been great on BA. They are very friendly and accommodating. I like that they have vegetarian options already in the menu. And the free wine is a nice perk.) I noticed (both directions of my trip) minor upgrades/ replacements needed on the plane itself (touch screen didn't work with touch; bathroom light didn't go on). However, this is one of my favorite airlines.

Everything was spectacular except the boarding. It was just a mob of people while all groups were called over the public address system.

The Britts are wonderful to fly with and the crew were very hospitable. Again, I really wish they had been able to retrieve my carryon bag from baggage claim before the flight so I could be in a less worrisome state of mind, but that's not on them. I completely understand. The window seats with the dimmable windows were very cool!

There was a delay for the San Francisco-London flight, but we were all informed via text and email. The staff was very friendly and nice and the food was good. I do recommend that the airline offer something without eggs or something vegan for the vegetarian meal option. A lot of Indians are lacto-vegetarian, while some could be allergic to eggs/dairy.

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

Information on your arrival and departure airports