$466 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 2/28. 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

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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 round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago1 stop$541
St. Louis
St. Louis1 stop$694
Chicago
Chicago1 stop$541
St. Louis
St. Louis1 stop$694

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

Tue, Mar 10 - Fri, Mar 20
TAP AIR PORTUGAL Logo
6:30 pm - 4:00 pm
LHR
-
ORD
26h 30m
1 stop
TAP AIR PORTUGAL Logo
9:15 pm - 5:30 pm
ORD
-
LHR
15h 15m
1 stop
$541TAP AIR PORTUGAL
Thu, Mar 12 - Sun, Mar 22
TAP AIR PORTUGAL Logo
4:30 pm - 4:25 pm
LHR
-
ORD
28h 55m
1 stop
TAP AIR PORTUGAL Logo
9:25 pm - 5:30 pm
ORD
-
LHR
15h 05m
1 stop
$542TAP AIR PORTUGAL
Mon, Apr 13 - Mon, Apr 27
Finnair Logo
2:45 pm - 10:17 pm
LHR
-
STL
13h 32m
1 stop
Finnair Logo
4:30 pm - 10:30 am
STL
-
LHR
12h 00m
1 stop
$694Finnair
Mon, Apr 20 - Thu, Apr 30
Finnair Logo
8:55 am - 5:21 pm
LHR
-
STL
14h 26m
1 stop
Finnair Logo
8:54 am - 6:25 am
STL
-
LHR
15h 31m
2 stops
$695Finnair
Wed, Apr 15 - Wed, Apr 22
British Airways Logo
9:45 am - 4:41 pm
LHR
-
STL
12h 56m
1 stop
British Airways Logo
8:03 pm - 12:15 pm
STL
-
LHR
10h 12m
1 stop
$711British Airways
Sun, Apr 19 - Sun, May 3
British Airways Logo
7:00 pm - 7:29 pm
LHR
-
STL
30h 29m
2 stops
British Airways Logo
8:03 pm - 6:50 am
STL
-
LHR
28h 47m
1 stop
$751British Airways
Tue, Apr 7 - Tue, Apr 14
United Airlines Logo
11:05 am - 11:42 pm
LHR
-
PAH
18h 37m
2 stops
United Airlines Logo
5:00 am - 7:40 am
PAH
-
LHR
20h 40m
2 stops
$997United Airlines
Mon, May 11 - Sun, May 17
United Airlines Logo
10:50 am - 8:57 pm
LHR
-
MLI
16h 07m
2 stops
United Airlines Logo
2:40 pm - 9:00 am
MLI
-
LHR
12h 20m
1 stop
$1,133United Airlines
Tue, Apr 7 - Tue, Apr 14
Lufthansa Logo
7:30 am - 9:08 pm
LHR
-
PIA
19h 38m
2 stops
Lufthansa Logo
1:20 pm - 6:45 am
PIA
-
LHR
11h 25m
1 stop
$1,222Lufthansa
Thu, Apr 9 - Thu, Apr 16
Lufthansa Logo
1:30 pm - 11:57 pm
LHR
-
MLI
16h 27m
2 stops
Lufthansa Logo
7:24 pm - 11:45 am
MLI
-
LHR
10h 21m
1 stop
$1,256Lufthansa
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.

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 $519 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 72 hours was $519.

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.

No, with an average price for the route of $840, 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 September, when tickets cost $594 (return) on average. On the other hand, the most expensive months are July and December, when the average cost of round-trip tickets is $857 and $806 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, Wednesday is the cheapest day to fly on average and Monday 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 2 weeks before departure, which saves you about 23% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$461
Best time to beat the crowds with an average 1% drop in price.
Most popular time to fly with an average 17% increase in price.
Flight from London Heathrow Airport to Chicago O'Hare Airport

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.

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

    The cheapest time of day to fly to Illinois is generally in the morning, when round-trip flights cost $824 on average. Morning departures are around 13% 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 $943.

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.
7.6
Austrian AirlinesOverall score based on 900 reviews
8.1Crew
7.3Comfort
7.6Boarding
6.8Food
6.8Entertainment
Airline reviews

My Austrian Air flight from Montenegro to Vienna was delayed by three hours because their plane de-icer was broken and they had to wait for the sun to come up before the ice could melt. This meant we missed our United flight altogether. So I can't speak about United, but I was not impressed by Austrian Air. They made us check in two carry on bags for a 60% full flight, and the bags didn't find us in the US for ten days. The re-routing they arranged included an extra leg, a midnight taxi ride across New Jersey and New York, and a five hour sleep in a hotel. Not impressed.

2.0 MediocreNate, Jan 2026
GSP - IAD
Read more Austrian Airlines reviews

My Austrian Air flight from Montenegro to Vienna was delayed by three hours because their plane de-icer was broken and they had to wait for the sun to come up before the ice could melt. This meant we missed our United flight altogether. So I can't speak about United, but I was not impressed by Austrian Air. They made us check in two carry on bags for a 60% full flight, and the bags didn't find us in the US for ten days. The re-routing they arranged included an extra leg, a midnight taxi ride across New Jersey and New York, and a five hour sleep in a hotel. Not impressed.

Most of the crew members were rude, flight arrived late and we missed our connecting flight, they damaged my friends suitcase so badly that two wheels had been destroyed.

Excellent flight. The crew was exceptionally attentive and organized. Attention to details is unmatched.

Great! They got my vegetarian meal right, flight was comfortable, they helped store my heavy luggage. Pleasant crew and flight staff.

I did wish they would give us the entire little bottle Bailey's instead of just have 1/2 bottle at a time

The flight was delayed for 30 minutes with no apparent reason. There is no entertainment at all, and no USB or electric outlets for charging your phone or tablet.

They had me unpack a handbag 2 lbs overweight into another handbag 8 lbs underweight for a Bible.

My flight was canceled and even though I paid אם KAYAK you didn't even answer me and obviously didn't refund my money. I will never buy a ticket through you again.

One thing I really liked about Austrian Airlines was that the flight attendants were very kind, and the in-flight entertainment offered many choices. One thing that could be improved is the meal service, since only a vegetarian option was offered — it would be better to have at least two choices

Despite the booked seats in front of the land we were moved to the back of the plane even first like 8 lines were totally without pasangers. When I tried to sit on empty seat flight attendant asked me to go to my dedicated seat in the fully crowded back of the plane. She was not able to explain why. Food was very poor on flight LAX - VIE.

The gate agent had a really bad attitude and refused to help me get on the standby list. She just handed me a card and said I needed to call a number. I asked her to help with the AA app on my phone and she just shrugged and said she didnt know. After a few phone calls, I eventually just went to a different gate agent on the other side of the terminal and got the help I needed.

Overall, my last three trips on American Airlines have all been either delayed or "rescheduled" due to mechanical issues. At least on delay caused me to miss two possible connecting flights each later than the first. My last option for my last connection required the assistance of the onsite service desk (O'Hare Airport). The wait time for the service desk was such that it jeopardized getting booked on the last connecting flight available for the night. Suffice it to say, my latest experiences with American Airlines have caused me extensive loss of productive business and personal time and can therefore be classified as significantly less than satisfactory.

The flight attendant use 1.5 hours to answer my call. My dirty food tray was unattended.

The flight was completely full. Crew was not happy. Everyone was rude and brusque. Travelling with an arm in a cast and seating in the first row of economy cabin (in front of the separation) I needed help retrieving my tray for the meal. A staff member literally threw the tray on my lap, without helping to take out the tray. Boarding was messy, with 300 people waiting in an encloses space with low ceiling. I will try to avoid AA next time I have a long flight.

The business class seats are dated and uncomfortable. The space is bare minimum and there is absolutely no privacy. For $4K, this is not what I expect.

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

Lost luggage after 2 days no word leaving on cruise no stuff or clothes

Staff's did their best to make everyone comfortable and I appreciate them for it

Pathetic check in experience once again. Not enough staff scheduled at bag drop or for special assistance at LHR. Really need to rethink the whole self check in procedure. The crew was good. A very decent selection of special meals in this leg as compared to the JFK-LHR leg.

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

All aspects were excellent - it helped that the flight was only 2/3 full and I had no one sitting in my row. The Pre-check (US Passport Control and Customs) in Dublin made everything so easy when we arrived in Chicago.

I love the direct flights. It saves a lot of hassle and allows immigration and customs in Ireland, making arrival much easier.

One of the best flight experiences I've have had in along time. Would fly with them again.

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.

So, the trip from Dublin to LA did not really happen because the flight took off before we could finish the transfer.

Very nice experience. Flight had good entertainment system and good food options. Customer service was very friendly and nice as well.

The connection time between the regional flight (from Newcastle) to an international flight (to The States) was too short. To require as second security scan and customs clearance within an hour and 20 mins is not enough time to make the actual connection. We had a final boarding call the minute we walked out of US customs and had to sprint (with two small children) through 20 gates to make it in time before the door closed. The concept is great in theory to clear customs before leaving Europe, but the timing needs to be adjusted. We travel abroad frequently and won’t be using this route again. Thanks.

Like - the crew were nice Dislike - sitting on the tarmac for long periods after boarding and landing.

I was not admitted to the flight!!! i need a refund for this.

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.

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

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

Late takeoff, but on time landing. Lost bags, 3 days to find them, still in transit to my location. Power outlets broken, Wi-Fi not working, so much for working on the long flight.

Good. For a long flight. The comfort of the seat could be better. Also, the food was « normal » plane food. Not indian plane food unfortunately! Everything else was smooth and great.

The seats were comfortable. So many empty seats allowed for stretching out and sleeping. The onboard entertainment was pretty good. The cabin crew were so kind and kept the passengers well- hydrated, and well fed.

We had American Airlines on our return and it was confusing if we were going with Aa or BA I had 2 different flight numbers and didn’t get our gate until it was boarding. So we were a bit nervous as the which it was

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 you need to know for your flight from Heathrow to Illinois

Information on your arrival and departure airports