$432 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 12/7. 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 round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$665
St. Louis
St. Louis1 stop$811
Chicago
Chicagononstop$665
St. Louis
St. Louis1 stop$811

Book Cheap Heathrow to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip 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 round-trip flight deals from Heathrow to Illinois

Thu, Nov 26 - Tue, Dec 1
British Airways Logo
11:00 am - 1:45 pm
LHR
-
ORD
8h 45mnonstop
British Airways Logo
9:50 pm - 11:35 am
ORD
-
LHR
7h 45mnonstop
$665British Airways
Fri, Dec 18 - Fri, Jan 1
TAP AIR PORTUGAL Logo
6:00 am - 3:30 pm
LHR
-
ORD
15h 30m
1 stop
TAP AIR PORTUGAL Logo
8:10 pm - 5:30 pm
ORD
-
LHR
15h 20m
1 stop
$666TAP AIR PORTUGAL
Mon, Nov 30 - Thu, Dec 3
British Airways Logo
3:40 pm - 6:45 pm
LHR
-
ORD
9h 05mnonstop
British Airways Logo
9:50 pm - 11:35 am
ORD
-
LHR
7h 45mnonstop
$667British Airways
Wed, Sep 9 - Tue, Sep 15
Icelandair Logo
1:05 pm - 6:15 pm
LHR
-
ORD
11h 10m
1 stop
Icelandair Logo
7:25 pm - 11:55 am
ORD
-
LHR
10h 30m
1 stop
$668Icelandair
Mon, Sep 7 - Mon, Sep 21
Icelandair Logo
9:25 pm - 6:15 pm
LHR
-
ORD
26h 50m
1 stop
Icelandair Logo
7:25 pm - 11:55 am
ORD
-
LHR
10h 30m
1 stop
$670Icelandair
Wed, Sep 2 - Wed, Sep 23
Lufthansa Logo
6:30 am - 1:25 pm
LHR
-
STL
12h 55m
1 stop
Lufthansa Logo
12:28 pm - 5:55 am
STL
-
LHR
11h 27m
1 stop
$811Lufthansa
Wed, Sep 2 - Wed, Sep 23
Lufthansa Logo
6:30 am - 5:06 pm
LHR
-
STL
16h 36m
2 stops
Lufthansa Logo
8:40 am - 6:55 am
STL
-
LHR
16h 15m
1 stop
$817Lufthansa
Wed, Jan 13 - Sun, Jan 17
United Airlines Logo
9:30 am - 1:38 pm
LHR
-
PAH
34h 08m
2 stops
United Airlines Logo
2:05 pm - 5:55 am
PAH
-
LHR
33h 50m
2 stops
$920United Airlines
Tue, Sep 8 - Tue, Sep 15
United Airlines Logo
4:00 pm - 1:20 pm
LHR
-
PAH
27h 20m
2 stops
United Airlines Logo
2:05 pm - 11:55 am
PAH
-
LHR
15h 50m
2 stops
$936United Airlines
Tue, Sep 8 - Tue, Sep 15
American Airlines Logo
2:45 pm - 11:19 pm
LHR
-
PIA
14h 34m
1 stop
American Airlines Logo
4:43 pm - 12:50 pm
PIA
-
LHR
14h 07m
1 stop
$1,095American 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 round-trip flight from London Heathrow Airport to Illinois?

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

Flight prices are below average for this route right now.

Flights to Illinois from London Heathrow Airport usually cost between $817 and $1,134 in November.
The lowest price found in the past 5 days was $665 on British Airways (Nov 26-Dec 1).

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 $625 round-trip. 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 5 days was $625.

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 round-trip flights cost $906 on average. On average, there is no price difference when choosing to fly in the morning or the evening on this flight route. 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 $946.

Can I save money by flying with a layover from London Heathrow Airport to Illinois?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $1,172 on average.

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 $615 (return) on average. On the other hand, the most expensive months are July and June, when the average cost of round-trip tickets is $1,036 and $949 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.

For London Heathrow Airport to Illinois, Thursday is the cheapest day to fly on average and Saturday is the most expensive. Flying from Illinois back to London Heathrow Airport, the best deals are generally found on Tuesday, with Saturday being 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 the 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

Low season

January

Cheapest flight

$432
Best time to beat the crowds with an average 7% drop in price.
Most popular time to fly and prices are also 7% 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 travelers 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 travelers 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 round-trip 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.

Top tips for finding cheap flights to Illinois

  • Looking for a cheap flight? 25% of our users found tickets from London Heathrow Airport to the following destinations at these prices or less: Chicago $731 one-way - $858 round-trip

Reviews of the top 5 airlines serving 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.
7.3
Aer LingusOverall score based on 1681 reviews
7.2Comfort
7.4Boarding
7.0Entertainment
8.1Crew
6.7Food
Airline reviews

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

8.0 ExcellentJmH, Jan 2026
LHR - ORK
Read more Aer Lingus reviews

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

Plane features were VERY old and outdated. footrest cushion was completely lose, plane felt dirty and a bit grimy. i was in business class. the lead flight attendant, Mary made a few announcements that didn't seem to put the cabin at ease (it didn't necessarily bother me, but could have bothered others). she said "the seat cushions aren't FDA approved, so you have to put them on after we take flight." everyone had already applied the seat cushions, and saying something isn't approved for flight may cause alarm. she also said at one point over the announcement ... "we can't get up because we are too afraid of the jet stream impacts" -- again, not helpful to those who are nervous fliers.

Extremely comfortable airplane, everything looked brand new, how lovely! My seat in Premium Economy was ever so comfortable, I did not suffer the usual backache I suffer when doing the transatlantic flight. It felt like seating in a reclining armchair. I loved the foot rest, did not need to use the portable device I usually carry along with me to replace one. I loved the spaciousness in front of me, and that there were only two seats (Instead of 3 in coach) in the window row, wow what a difference in comfort. Coach seats are always just a little narrow for my hips. The support of the cushions was great, firm and offered good support . It was easy to come out of my aisle seat, although I'm 70. The staff was courteous, both meals were delicious, very carefully prepared, and creative (fruit + cheese for the second meal, instead of the usual bread sandwich)

Awful customer service, horrible experience. We travel a lot domestic & international- worst flights to/from ever. Brief bkgd as Inhate to relive this experience: booked and chose 2 seats 4 months prior in Premium Economy - last row end seats close to bathroom, no one behind us, plenty of legroom;, underwear storage — flown this was on other airlines, love it. We receive notice 4 days before scheduled overseas flight - plane has changed, new seats assigned. Seats are split into single seats, opposites of the plane, FRONT Row so no reachable storage. Called BOTH British Air & America. American “switched planes and the seats you want are taken;” British Air “Yes, we’ll be glad to accommodate you (type type type). Just ask at the Gate and someone will give you new boarding passes with seats together in middle, OK?” — OK. —At Gate the attendant looks us up saying “No, it is an overbooked flight and yours are the only seats available.” But but but wait, “We were TOLD our seats had been switched and seated together?” Gate attendant “Well they were wrong and don’t change your seats. Your original seats are where you’ll sit.”. Right. No help WHATSOEVER. We sit opposite on way there, wife VERY disgruntled, a Tol 5 worst ways to start a 3-week bus tour of UK. We promise to NEVER FLY AMERICAN OR BROTISH AIR EVER, and we have 3 more extensive trips planned..

I understand that there is a catering issue - water should be the minimum stock. During the flight, not once that the attendants came through with water. The conversations in the kitchen were very loud and they were swearing. I do not expect any white glove service, at the minimum, we should be cordial. It was almost an inconveniece that we were on the flight. And it made us feel if you even dare question us, we'll make you deplane.

Flight, food and crew were all good, friendly and very satisfactory.

Very clean and comfortable cabin. Amazing Mediterranean salad for lunch before landing. Great range of films to watch. Really quiet and easy to sleep on the flight also. The initial food was a bit weird: odd fried chicken pieces in some weird white gloop, but that would be my lack of cultural knowledge on the grub. Salad more than made up for it at the other end. Staff were super attentive and helpful. Great and easy flight

Fantastic. I am low vision and was impressed with how helpful and accommodating the service tam was. It was super appreciated! I was pleasantly surprised about how delicious the food was. Like, “I wish I had more even though I’m no longer hungry” delicious. 100% enjoyable trip.

Good with British Airways - terrible with American Airlines! Stood at gate for “mechanical problem” - plane delayed. Had to check my personal belonging with 5 empty bins available in plane, desk staff rude!!! Toilet not working- asked “to use working toilet sparingly - it may overflow in cabin!”

Lisbon airport is excellent. Sad we don’t have better airports in US.

I paid to upgrade my seat to premium economy, it was well worth the extra cost. I have vegan meals and they were very good. Most of the flight attendants were very attentive, but for one was slightly rude. I thought the service was great overall and they had a nice movie selection for entertainment

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