£356 Find Cheap Flights from London Heathrow Airport to Illinois – Compare and Save

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 11/9. 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.
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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£493
Moline
Moline2 stops£740
Peoria
Peoria2 stops£817
Champaign
Champaign2 stops£788
Springfield
Springfield1 stop£856
Bloomington
Bloomington1 stop£768
Chicago
Chicago1 stop£493
Moline
Moline2 stops£740
Peoria
Peoria2 stops£817
Champaign
Champaign2 stops£788
Springfield
Springfield1 stop£856
Bloomington
Bloomington1 stop£768

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

Mon, 11 Jan - Tue, 18 May
Icelandair Logo
12:15 - 17:20
LHR
-
ORD
11h 05m
1 stop
Icelandair Logo
19:25 - 20:20
ORD
-
LHR
18h 55m
1 stop
£493Icelandair
Mon, 7 Sep - Mon, 21 Sep
Icelandair Logo
21:25 - 18:15
LHR
-
ORD
26h 50m
1 stop
Icelandair Logo
19:25 - 20:20
ORD
-
LHR
18h 55m
1 stop
£494Icelandair
Sat, 26 Sep - Sat, 3 Oct
Lufthansa Logo
14:05 - 10:15
LHR
-
ORD
26h 10m
1 stop
Lufthansa Logo
17:07 - 10:25
ORD
-
LHR
11h 18m
1 stop
£495Lufthansa
Sat, 26 Sep - Sat, 3 Oct
Lufthansa Logo
14:05 - 10:15
LHR
-
ORD
26h 10m
1 stop
Lufthansa Logo
21:30 - 11:55
ORD
-
LHR
8h 25mdirect
£495Lufthansa
Wed, 9 Sep - Wed, 9 Sep
United Airlines Logo
08:40 - 15:55
LHR
-
ORD
13h 15m
1 stop
United Airlines Logo
18:15 - 10:40
ORD
-
LHR
10h 25m
1 stop
£497United Airlines
Wed, 7 Oct - Sun, 11 Oct
Multiple Airlines Logo
10:20 - 21:25
LHR
-
ORD
17h 05m
2 stops
Multiple Airlines Logo
22:25 - 21:40
ORD
-
LHR
17h 15m
2 stops
£501Multiple Airlines
Thu, 17 Dec - Fri, 1 Jan
TAP AIR PORTUGAL Logo
18:30 - 15:30
LHR
-
ORD
27h 00m
1 stop
TAP AIR PORTUGAL Logo
20:10 - 17:30
ORD
-
LHR
15h 20m
1 stop
£503TAP AIR PORTUGAL
Wed, 30 Sep - Wed, 7 Oct
Multiple Airlines Logo
10:20 - 21:25
LHR
-
ORD
17h 05m
2 stops
Multiple Airlines Logo
22:25 - 21:40
ORD
-
LHR
17h 15m
2 stops
£506Multiple Airlines
Tue, 15 Dec - Sun, 3 Jan
TAP AIR PORTUGAL Logo
18:30 - 15:30
LHR
-
ORD
27h 00m
1 stop
TAP AIR PORTUGAL Logo
20:10 - 17:30
ORD
-
LHR
15h 20m
1 stop
£516TAP AIR PORTUGAL
Mon, 21 Sep - Wed, 23 Sep
United Airlines Logo
08:40 - 12:35
LHR
-
ORD
33h 55m
1 stop
United Airlines Logo
10:50 - 06:55
ORD
-
LHR
14h 05m
1 stop
£517United Airlines
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 September.

Flight prices are below average for this route right now.

Flights to Illinois from London Heathrow Airport usually cost between £555 and £830 in September.
The lowest price found in the past 5 days was £493 on Icelandair (24 Sept–5 Oct).

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 5 days was to Chicago, at £495 return. The most popular route is from London Heathrow Airport (LHR) to Chicago O'Hare Intl Airport (ORD), and the cheapest return airline ticket found on this route in the last 5 days was £495.

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 £665 on average. Morning departures are around 1% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the morning, which is peak travel time and where the average cost of a ticket is £694.

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 £779, 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 £462 (return) on average. On the other hand, the most expensive months are July and June, when the average cost of return tickets is £778 and £713 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 Thursdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Illinois, Monday is the cheapest day to fly and Saturday 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 4 weeks before departure, which saves you about 19% 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 Heathrow Airport to Illinois

Low season

January

Cheapest flight

£356
Best time to beat the crowds (11% less expensive on average)
Most popular time to fly and prices are also 5% lower 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 10052 reviews
7.3Comfort
8.1Crew
7.7Boarding
7.1Entertainment
6.6Food
Airline reviews

Very friendly and helpful staff on board and United was excellent when I missed my onward flight due to the delay in London. Very well organised meant much less stress

8.0 ExcellentMarianne, May 2026
LHR - DEN
Read more United Airlines reviews

Very friendly and helpful staff on board and United was excellent when I missed my onward flight due to the delay in London. Very well organised meant much less stress

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

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

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

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!!

Our experience on United Airlines was extremely poor. The plane was extremely cold throughout our entire flight- which multiple people complained about- and we had to wait 2 hours to get a blanket which was too thin and barely helped warm us up. As well as this, none of the entertainment features were working so we had to sit through a roughly 10 hour flight with nothing to keep our attention, including the actual flight path screen. It was an extremely disappointing experience and I would hope that this gets fixed if we ever choose United Airlines again.

Cabin crew was very friendly, requests were satisfied promptly and cheerfully, and the cabin was reasonably clean when I boarded. The United lounges at Newark and Heathrow are always well-run and comfortable, especially Newark. I look forward to the new lounge that will be part of the rebuild of Terminal 2 at Heathrow.

The senior flight attendants were amazing. Totally different vibe from other carriers. Easy 10 hour flight in Business Class. Great food. Good humor as well.

I was lucky to sit in a seat with legroom in economy . The airplane felt like it was 100 years old, seats were very basic, barely reclined. Food was alright , staff was ok but not the friendliest. But all in all ok trip, perfectly on time

Late start, late arrival and very uncomfortable seating. If they schedule a takeoff at a specific time, how can they not know the traffic at the airport will be heavy and delay flights at that time? I paid for legroom but when seated next to an oversized person, I had no elbow room. Also, who wants to rub hips with a large stranger for over 2 hours? I ended up leaning toward the aisle the entire flight and being bumped every time someone passed by. Paying for legroom should include side-to-side space, too. This happened on both domestic flights I had within the past 2 weeks.

Like getting a bus. No great luxury but will get you there

Got us to destination alive, albeit a bit late. Luggage was left behind. No live tracking app available (available on some other airlines). Supposedly going to be delivered in next couple of days.

I had zero issues with the flight. I did have issues with the staff at the airport. We missed out flight due to a delay with another airline. Talking to the staff and trying to get a new flight arranged was challenging. One guy was able to try to help us and got us on a new flight, but other staff was dismissive and clearly let us know it wasn’t their problem. All I kept thinking was… this is why air lingus has such a poor customer service reputation. I will be avoiding this airline in the future.

I liked that I went thru customs in Dublin instead of having to do that in LA.

Baggage fees are deceptive! When I booked this flight, I purchased two tickets and had indicated that I wanted one checked bag. That increased the ticket price by about $100 PER TICKET!. When we went to check in, I was told that I could only check ONE bag, even though I had purchased TWO tickets. I had to pay an additional $50 each way for my wife’s bag. In my opinion, I paid twice for her bag.

Delays resulting in missed connecting flight. Attendant failed to arrange special assistance as promised to get us on connecting flight. Robyn was the particular attendant.

Very good except for the boarding process which was more hectic than it should have been

This was the most expensive economy flight per minute of flight time ever. But the quality was lacking. Extremely Aer Lingus rude staff at LHR said that the flight from London to Dublin (Ireland) was “NOT international.” Horrified at the colonial and imperial perspective. Seats were dirty with trash in seat pockets. Airline doesn’t clean or care about hygiene and safety.

The ease of boarding was good. I wish they had something to eat on the plane.

Really helpful staff at the airport and the flight was comfortable with good entertainment options and food service

1. No food on a 8 hr flight is a travesty! The fare was not that low. 2. The entertainment was pretty bad and you had to buy headphones!!! 3. Only 2 toilets for the whole Economy section!!

At least one soda free, felt like I was nickeled to death.

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.

Comfort of seats is not good. Like sitting on a rock for 6 hours. Also no in flight food and limited beverages unless you pay is not nice. Need flight to be dark during the “night” but attendants don’t ask for shades to be lowered..

For an economy lite experience, it's by far the best I've had. New planes, clean, great destinations. Very happy to have discovered Iceland Air.

Smooth efficient airline. Think they should have their own bag drop as the queue took 30mins to bmscan and drop

Good. Lacking overhead bin space. No food offered but you can order online or in flight and pay for snacks.

did internet check in but still had to get checked in at the counter and this was not the first time. Bummer!

We had to be bussed to the plane. And it was raining. Not a pleasant experience.

Paying $75 for my bag is disgusting. Got off ground late so I missed my connections. Kept us waiting for passengers in the cold. Will not use them again.

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.

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.

Not what I expected for the last leg of a $5100 business class experience. Boarding was a nightmare. The flight was delayed and I had to keep checking my email to ensure I was at the right gate since the airline or the terminal had no clue until 15 mins prior to boarding. Food was gross, limited drink options.

Flights scheduled with impossible connections - Lufthansa apparently believes it takes 7mins to change terminals, go through passport control, re-clear security and walk 1.8kms…..and everything will work perfectly (which it never does at Frankfurt). No staff on hand to assist with transfers on delayed flights. No transfer guidance provided by app. No compensation offered for 6hr delay to connecting flight.

Crew were friendly and very helpful Plane was clean and the legroom is standard. Overall a good flight, no complaints.

Other than problems with checking in and uploading passport info everything was great. It would be nice to be able to manually input passport info. Often while traveling the bandwidth has problems uploading pictures

Boarding was a zoo. London ground crew was useless. Poor communication regarding where to line up. We were group 2, and everyone was jammed in together. Ground crew didn’t seem to care.

Horrible flight attendant in back of economy that screamed at me, have already reported to United. Horrible food - for Gluten free, why would you assume the person is vegetarian? I was served some kind of horrible curry bean paste and multiple cold rolls and soggy vegetables with no seasoning... um no!

Knowing that there was weather in other areas of the world, united airlines should have planned better than it did. The flight was 5 hours late. United has no regard for its customers

Flight itself fine, big problem with KAYAK. Revised e-ticket sent in July stated departure LHR 10:55, arrival SFO 13:45. (a believable local arrival time given flight length and time difference). When we got to LHR there was no 10:55 flight to SFO and were advised that in fact flight LH2473 was arriving in MUNICH at 13:45pm, and that we would need to get a connecting flight arriving in SFO at 18:55 local time - over 5 hours later than expected. 1) you the booking agent made an error on the revised e-ticket you sent, omitting the Munich stopover and incorrect SFO arrival time. 2) I booked a DIRECT flight and 3) we had to cancel plans this end as a result, even though the team at LHR did a great job moving us to a later direct flight getting us in 2 hours earlier than the flight from munich would have.

I will never want to book with these people. They are arrogant and rude. Food was really really bad, crew was even worst

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

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

Unfortunately, my flight was cancelled because of some sort of emergency over the Atlantic and had to return to London. While I think British Airways made every effort to mitigate the situation, I must say it was still pretty unpleasant. I do appreciate the fact, however, that British Airways put my safety first…and I think the effort to correct a bad situation was very sincere. But I think the process might be handled better in future.

The seat pads are past there sell by date now and are uncomfotable. Also, with screens in the back of the seat, the seats shouldnt be able to recline as this puts rhe screen in your face.

As I have said it sucked, the ticket counter to have to find and pay for another airline to get home. Now I understand this happened over the weekend but they should have someone there to talk to us instead of throwing the regular crew under the bus.

Not so good with their baggage handling as they damaged one of my check in luggage

This flight from London to Chicago was actually on an AA airline. I did book through BA but the flight was AA. Great flight, hectic in Chicago, I wouldn't choose to fly through Chicago again, but that's not the airlines fault. The flight itself was great.

Seats were way too small. I got claustrophobic waiting for trash from meal to be taken away. I couldn't move to even close my tray until trash was taken.

The whole experience was very disappointing. Drinks could have been served and offered more frequently. The seats were reasonable but considering I paid for premium economy, I felt cheated. I flew premium economy with Japanese Airlines ANA 5 years ago and their service was by far, superior. We had access to the club lounge, better seats and excellent service. Out of 10, I would rate the experience as 4. Everything felt cheap and the Airbus aircraft are far better and more comfortable

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

Information on your arrival and departure airports