Cheap flights from Chicago to London from £316

In general, January is the cheapest month to fly from Chicago to London Heathrow Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around £147. The month of February is another great option to travel to London Heathrow Airport, with average flight prices from Chicago averaging around £232.

On average, the least expensive day to fly to London Heathrow Airport from Chicago is on a Sunday. momondo users have found tickets for Sunday departures for as low as £510. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Friday as prices are generally higher than usual. According to our data, the average ticket price to London Heathrow Airport on Friday is £724.

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from Chicago to London Heathrow Airport in the evening for as low as £556. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are £671 on average. Flights to London Heathrow Airport from Chicago in the afternoon are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from Chicago O'Hare Intl to London Heathrow for the best Chicago - London Heathrow flight prices

You are more likely to see cheaper flights to London Heathrow Airport from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around £591 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Chicago for as low as £512 on momondo.

No. A direct flight is the cheapest option for a flight between Chicago to London Heathrow Airport.

As of May 2026, prices for Chicago to London Heathrow Airport flights are approximately 4% more expensive when compared to flights at the same time last year.

JetBlue, Icelandair, and United Airlines are the most popular carriers operating from Chicago to London Heathrow

British Airways, Aer Lingus and United Airlines are the top three most popular airlines that fly to London Heathrow Airport from Chicago according to our data. British Airways is the first choice among our users, with 53% of people opting to fly with this airline when travelling to London Heathrow Airport. Keep in mind that there are 6 different airlines that fly to London Heathrow Airport on a routine basis, so you have a few additional options to choose from.

Historically, on average around 25% of flights between Chicago and London have experienced a delay on any given week. The average delay length over the past 12 months has been 174 minutes.

Generally, flights departing in the early afternoon tend to experience fewer delays. Flights departing at night have, in the past, seen delays more frequently in comparison.

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

According to our data, United Airlines have had the fewest delays on this route over the last 12 months, with about 25% of their flights experiencing any sort of delay.

As of May 2026, there are 57 flights per day flying from Chicago to London Heathrow Airport. The most common time of day flights depart is 17:00, with 67% of flights taking off in the evening.

The number of flights available between Chicago and London Heathrow Airport is 404 per week as of May 2026. The most frequent departure day is Mon, with 14% of weekly flights leaving on this day.