$467 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 9/2. 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

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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$718
St. Louis
St. Louis1 stop$1,026
Chicago
Chicago1 stop$718
St. Louis
St. Louis1 stop$1,026

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

Fri, Oct 9 - Mon, Oct 19
Scandinavian Airlines Logo
6:40 am - 4:10 pm
LHR
-
ORD
15h 30m
1 stop
Scandinavian Airlines Logo
7:15 pm - 5:40 pm
ORD
-
LHR
16h 25m
1 stop
$718Scandinavian Airlines
Wed, Nov 11 - Tue, Nov 17
Scandinavian Airlines Logo
10:20 am - 4:45 pm
LHR
-
ORD
12h 25m
1 stop
Scandinavian Airlines Logo
7:15 pm - 9:40 pm
ORD
-
LHR
20h 25m
1 stop
$720Scandinavian Airlines
Wed, Nov 11 - Wed, Nov 18
Scandinavian Airlines Logo
10:20 am - 4:45 pm
LHR
-
ORD
12h 25m
1 stop
Scandinavian Airlines Logo
7:15 pm - 4:00 pm
ORD
-
LHR
14h 45m
1 stop
$721Scandinavian Airlines
Thu, Sep 10 - Thu, Sep 24
TAP AIR PORTUGAL Logo
4:35 pm - 4:00 pm
LHR
-
ORD
29h 25m
1 stop
TAP AIR PORTUGAL Logo
6:00 pm - 12:45 pm
ORD
-
LHR
12h 45m
1 stop
$723TAP AIR PORTUGAL
Thu, Nov 12 - Mon, Nov 16
American Airlines Logo
2:10 pm - 5:05 pm
LHR
-
ORD
8h 55mnonstop
American Airlines Logo
1:15 pm - 6:15 am
ORD
-
LHR
11h 00m
1 stop
$725American Airlines
Mon, Jul 13 - Thu, Jul 23
American Airlines Logo
9:15 am - 4:10 pm
LHR
-
EVV
12h 55m
1 stop
American Airlines Logo
7:08 am - 6:15 am
EVV
-
LHR
17h 07m
2 stops
$1,010American Airlines
Sat, Jun 27 - Mon, Jul 6
British Airways Logo
7:30 pm - 11:59 pm
LHR
-
STL
34h 29m
2 stops
British Airways Logo
7:22 pm - 2:25 pm
STL
-
LHR
13h 03m
1 stop
$1,032British Airways
Sat, Jul 4 - Fri, Jul 10
British Airways Logo
9:15 am - 5:02 pm
LHR
-
STL
13h 47m
1 stop
British Airways Logo
7:56 pm - 12:15 pm
STL
-
LHR
10h 19m
1 stop
$1,033British Airways
Tue, Jun 30 - Mon, Sep 28
Lufthansa Logo
6:30 am - 4:58 pm
LHR
-
PIA
16h 28m
2 stops
Lufthansa Logo
4:05 pm - 11:55 am
PIA
-
LHR
13h 50m
1 stop
$1,058Lufthansa
Tue, Jun 30 - Mon, Sep 28
Lufthansa Logo
6:30 am - 4:58 pm
LHR
-
PIA
16h 28m
2 stops
Lufthansa Logo
4:05 pm - 4:40 pm
PIA
-
LHR
18h 35m
2 stops
$1,064Lufthansa
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 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 5 days was to Chicago, at $633 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 $633.

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 morning, when round-trip flights cost $908 on average. Morning departures are around 8% 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 $991.

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 $1,044 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 $374 (return) on average. On the other hand, the most expensive months are June and December, when the average cost of round-trip tickets is $1,970 and $1,227 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 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 2 weeks before departure, which saves you about 20% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 23 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$467
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 18% increase in price.
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 $680 one-way - $1,044 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 1598 reviews
7.4Boarding
6.7Food
7.2Comfort
7.0Entertainment
8.1Crew
Airline reviews

Vegetarian food option was very poor. Effectively, overcooked rice ("risotto"). Zero protein which is always disappointing with no vegetables and poorly seasoned. Basically had lots of carbs on 6-hour flight. Not acceptable for business class in 2026. Flight was otherwise very good.

8.0 ExcellentAnonymous, Jun 2026
DUB - BOS
Read more Aer Lingus reviews

Vegetarian food option was very poor. Effectively, overcooked rice ("risotto"). Zero protein which is always disappointing with no vegetables and poorly seasoned. Basically had lots of carbs on 6-hour flight. Not acceptable for business class in 2026. Flight was otherwise very good.

Small plane. Tight seating . What can one say except that it was fast!

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.

The passport control process in Lisbon ranks as a 1 on a 1 to 5 scale. Terrible. In line 2 hours and still missed our first flight. Next day, 1.5 hours but we made the flight. The Business Class food was poor. Unidentifiable. Not tasty at all. Unacceptable in BC. Attendants were adequate. Flight left late and arrived late. After this trip, we will not be flying TAP nor will we be connecting through Lisbon.

On both flights, TAP Air Portugal messed up the seating choices that I paid for. They acknowledged that I had purchased seating, that they were errant in ensuring my choices, but told me nothing could be done about it. When I asked to be refunded, I was directed to "talk to someone from Air Portugal" Mon-Friday, and then I was dismissed. No help, no phone number provided to me. I was very annoyed both times and feel cheated.

Business class seats aren't comfortable. Food was not good.

Didn't make announcements during boarding, flight attendant seemed annoyed when I asked for water. Too many hours between flights. Confusing check in at the Lisbon airport.

The chicken was so dry it was impossible to eat. No substitute was offered. The port to charge my phone was broken and all I got was a shrug from the crew. The entertainment system was glitchy and subtitles didn’t load. Crew seemed fully uninterested and unfriendly.

Delayed at the beginning and the end and almost missed our connection

The crew was great. There was a big guy sitting next to me who was hanging over my side of the armrest the entire time. Maybe some information about "Be considerate of your neighbors, this is tight space, be kind". The breakfast sandwich was not appealing at all.

Kayak let me choose these flights on TAP but then after 2 months, cancelled my flights because they didn't think 90 minutes was enough time for the connection. I notice that neither flight was actually cancelled. Just my reservation. Why let me go through all of that effort to find the right flights for us, only to cancel it from underneath us 2 months later leaving us scrambling to find an alternative?

It was a good experience overall. We were however delayed by over 3 hours due to a security issue with one of the passengers inadvertently leaving a power bank in a luggage she was using as carrying on but then had to be moved int check in due to spacing issues. The airline staff had requested that she checked her bags in, but should have reminded her about removing all hazardous material like her power bank. When she eventually remembered as we were on the plane, we had to turn back and go through security all over again. Hence delaying our takeoff. The incident could have been prevented if staff reminded these passengers to remove their power banks.

Bad. They gave me a voucher for food to use at the airport but didn’t have time since I had to catch the other plane. No refunds and lack of communication

Very hard to beat a British Airways international flight…the crews are always so amazing! One flight attendant that really stood out was Emma…she was very personable and accommodating with any request we had!!

The passport line was so long that many of us were concerned about missing our flight and some did. It would've helped if a AA representative had gone to the passport check-in sooner to advise that boarding was closing and those flying that were stuck back in the line, needed to come forward with apologies to others. An AA representative did do that but only after boarding had already closed. (They delayed take-off so that more who were running with carry-ons could get to the gate - especially stressful for older people!) Then to be crammed into a seat with barely enough leg room for a thin woman, 5'7", like me, much less for a taller, bigger person was not comfortable, especially if the person in front decided to lean back. Crew was fine, food and entertainment also.

The seat when "flat" was not flat and pad was too thin to cover it.

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..

They lost my bag. ... And I asked them 3 times to 3 different people if my checked bag will maKe it all the way - they all confirmed and at the end it was left at the connection... Bravo

British Airways is an excellent airline. Comfort, food and airline personnel.

Older airplane with worn out seats. No entertainment system at all. Connecting to Wi-Fi was problematic and hit and miss.

An delay of almost 3 hours while passengers were already in the plane kept us very uncomfortable. The food was also very limited. A bad experience overall.

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.

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

The legroom was lacking and the entertainment system lacked adequate selection of older films. Modern films are generally not very good.

Perfect airline, super friendly, great service, tasty food. Would fly again.

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.

Lovely big plane. Excellent take off and landing. Cabin crew were so nice. Flight in time no delays

Because our ABZ-LHR flight was cancelled by BA for reasons they refuse to tell us--not weather--we did not make this flight and were booked on the following day. BA offered no assistance to us on the phone or in the airport, and we had to find a hotel at Heathrow on our own.

Horrible - flight was delayed by 6 hours - we boarded, were made to de-board due some technical fault; aircraft changed; special meals request on new flight - all went awry. Landed in Dulles airport; breezed thru immigration; as Business Class passengers or baggage was delivered almost 90 minutes after landing; air tags indicated the bags were just near the carousel but the unhelpful BA staff - Maria and Ghina refused to give any update - palming it off on some imaginary invisible “manager” despite air tags evidence showing it right there. So about 50-60 passengers waiting and getting infuriatingly impatient for their bags coz one container was not delivered. Finally after much argument by some other passengers Maria condescended to go to the “ramp” and within 5 minutes the baggage was delivered miraculously. Question is why couldn’t she have done it one hour earlier ? Poor poor experience once again on Business Class BA.

Cheap Flight Fares would not provide booking info. I canceled the reservation and we arbitrated with American Express. They provided erroneous info to Amex and it was determined that C.F.F. deserved the price of the ticket. Worse experience I've ever had.

Seating space is appalling. Seats and all surrounding area in "Economy" is built for individuals shorter than 4' 10" and below 120 lbs. Ridiculous. While I'm not expecting fine dining, the food was the worst airplane food that I can recall.

Business class lounge for my gate was closed and no email was sent, causing me to walk back and forth to different gates, etc for over 20 minutes one way. Flight entertainment was mediocre with very poor choices especially for business class cabin. Original flight was cancelled and rebooking was difficult and no reason given for cancellation.

Very comfortable flight and simple and directed one way and back. Amazing price.

We loved our flight attendant, Emma from Scotland, the meal and entertainment offerings were wonderful, the flight was smooth, and enough leg room to stretch. We would fly with you again!

Los Angeles to London. 25th of April 2026. Business class. I was flying backwards with a complete stranger snoring next to me. In Business class. Males and females, strangers lying next to each other. Seats were backwards. I paid for comfort. I got dizziness and stress.

Long line with check in at the DIA British Airway counter.

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

Information on your arrival and departure airports