Cheap flights from Belfast to London from £29

The month of March is, on average, the cheapest month to fly to Southampton from Belfast, with most prices found around £97. If you’re not able to fly to Southampton in March, then September is your next best option. Flight prices from Belfast to Southampton during September average around £101.

Our data shows that Thursday is the least expensive day to fly to Southampton. Tickets to fly out on this day can be as low as £84. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around £103. These prices are subject to change though, so be sure to set up a Price Alert for flights to Southampton.

According to our data, the cheapest time of day to fly to Southampton is at midday. momondo users have found flights departing from Belfast to Southampton at midday for as low as £122. 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 £141 on average. Flights to Southampton from Belfast in the afternoon are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from Belfast Intl to Southampton Eastleigh for the best Belfast - Southampton Eastleigh flight prices

You are more likely to see cheaper flights to Southampton from Belfast when booking weeks ahead of your departure date. In general, you can expect to find flights to Southampton for around £126 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Southampton from Belfast for as low as £49 on momondo.

There is only 1 cabin class available to choose from on Belfast to Southampton Eastleigh flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

easyJet and Aer Lingus are the most popular carriers operating from Belfast to Southampton Eastleigh

British Airways, easyJet and Aer Lingus are the top three most popular airlines that fly to Southampton from Belfast according to our data. British Airways is the first choice among our users, with 44% of people opting to fly with this airline when travelling to Southampton. Keep in mind that there are 6 different airlines that fly to Southampton on a routine basis, so you have a few additional options to choose from.

3 flights are operational daily from Belfast to Southampton as of March 2026. The most popular departure time for this route is 10:00, with 58% of flights per day taking off at midday.

As of March 2026, there are 24 flights per week flying from Belfast to Southampton. The most common day of the week flights depart is Mon, with 17% of flights taking off on this day.