The airline announced it will launch flights from London Stansted Airport to the European sunshine resorts of Faro, Malaga, Palma and Ibiza from 28 May.
The Saturday flights will be operated by the carrier's subsidiary BA CityFlyer on Embraer 190 jets.
They are based at London City Airport (LCA) - which is popular with business travellers - and are not being used at weekends.
BA also operates London flights from Heathrow and Gatwick.
Luke Hayhoe, a general manager at BA, said: "This is a fantastic opportunity for us to expand our London network and to give our customers even more choice of where to fly from this summer.
"Stansted is a growing airport and we will be offering a full scheduled service to some of the most popular European holiday destinations, complementing our existing services from other London airports."
Fares will start from £49 each way for a return trip with hand baggage only.
A spokesman for Manchester Airport Group (MAG), which acquired Stansted in 2013, said the Essex airport offers flights to more European destinations than anywhere else in the UK at over 170.
Stansted managing director Andrew Harrison added: "I am delighted to welcome British Airways to Stansted and very much look forward to the launch of its first ever scheduled flights from the airport in May this year.
"Since we acquired Stansted, our focus has been on attracting a wider choice of airlines and these new services to Faro, Malaga, Palma and Ibiza are strong additions to our route network.
"I'm sure these routes will be very popular with passengers from across London, Cambridge and the growing east of England region."
MAG is urging the government to improve rail connections into Stansted to encourage passengers and airlines to utilise the spare capacity at the airport before expansion at Heathrow or Gatwick can be delivered.