The BA City Flyer route will be launched along with three other new domestic routes from Belfast City Airport to Exeter, Glasgow, and Newquay airports.
The flights will start "over the next few months".
Tom Stoddart, Managing Director of BA CityFlyer, said: "We’re delighted to announce these new services from Belfast, which will enhance our regional network and maintain vital connections between Northern Ireland and other key UK destinations.
“We're sure these routes will be popular with customers getting away for a UK holiday this summer, as well as those visiting friends and relatives, and we’ll continue to listen to their feedback about where they want to travel.”
EasyJet has also announced that it will launch a new domestic flight from Leeds Bradford Airport to Belfast International airport this summer.
Flights from LBA to Belfast International Airport will take off from July 9 and will operate four times a week on Mondays, Wednesdays, Fridays, Sundays.
Ali Gayward, easyJet’s UK Country Manager, said: “We know our customers can’t wait to be reunited with friends and family or have more opportunity to explore the UK so this new route from Leeds should prove popular and will further strengthen our UK domestic network providing customers with even more choice.
“We also know it is important to our customers to be reunited with loved ones overseas so we continue to urge the UK government to add more countries to the Green list – which can be done safely - to make this possible.
“We continue to have some of the most flexible policies currently in place so customers can book with confidence and change their plans if they need to, making travel as easy as possible this summer.”
John Cunliffe, Aviation and Commercial Director at LBA, said: “I am delighted to welcome easyJet’s investment in Leeds Bradford Airport.
"The announcement of the new route to Belfast International Airport further strengthens the connectivity between Northern Ireland and the Leeds City Region, the largest economy in the UK outside of London.
"The service will have strong appeal to both business and leisure travellers alike, with an array of touristic opportunities for a UK staycation available at both ends of the route and, of course, a welcome opportunity to safely reunite with friends and family.”