Cheap flights from London to Portland from £275

The cheapest month to fly to Portland from London is in September. Flight prices, which tend to average around £557, are often lower during this time because this is during the off-season. If you don’t want to visit Portland in September, then you should wait until February to fly from London, when ticket prices are also cheap, with an average price of £575.

The cheapest day to depart on your flight to Portland is on a Wednesday when prices can be found for as low as £664. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Portland is Sunday, with ticket prices averaging around £792.

Flying to Portland from London at midday is the least expensive time of day to depart. momondo users have found prices as low as £685 when looking at flights departing at midday. Try not to purchase tickets in the afternoon because they tend to be around £750. Of course, these prices can vary depending on the time of year and what airport you fly to.

Fly from London Heathrow to Portland for the best London - Portland flight prices

You are more likely to see cheaper flights to Portland from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Portland for around £667 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portland from London for as low as £592 on momondo.

There are 3 cabin classes available to choose from on London to Portland flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 21% on your flight if you consider stops on a London to Portland flight.

As of March 2026, prices for London to Portland flights are approximately 2% more expensive when compared to flights at the same time last year.

SWISS, United Airlines, and Virgin Atlantic are the most popular carriers operating from London to Portland

British Airways, Virgin Atlantic and Icelandair are the top three most popular airlines that fly to Portland from London according to our data. British Airways is the first choice among our users, with 66% of people opting to fly with this airline when travelling to Portland. Keep in mind that there are 10 different airlines that fly to Portland on a routine basis, so you have a few additional options to choose from.

Historically, on average around 20% of flights between London and Portland have experienced a delay on any given week. The average delay length over the past 12 months has been 123 minutes.

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

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

According to our data, British Airways have had the fewest delays on this route over the last 12 months, with about 20% of their flights experiencing any sort of delay.

Reykjavik (KEF) was the most common stop: 45% of momondo users choosing one-stop flights on this route connected there.

Flights via Reykjavik (KEF) offer the lowest average return price of £445.

Flights connecting via Seattle (SEA) have the shortest average one-way travel time: 13h 13m.

San Francisco (SFO) has the shortest average stopover time for this route: 1h 23m.

2 flights are operational daily from London to Portland as of March 2026. The most popular departure time for this route is 13:00, with 100% of flights per day taking off in the afternoon.

The number of flights available between London and Portland is 20 per week as of March 2026. The most frequent departure day is Wed, with 35% of weekly flights leaving on this day.