Up to six flights a week will connect passengers from Northern Ireland with Cornwall and the south west of England throughout the summer.
Judith Davis, operations manager at Belfast City airport, said the announcement will be "welcome news for many".
"The launch of flights to Newquay from Belfast City Airport will be welcome news for many, giving passengers the option to holiday closer to home, reconnect with family and friends, and take a relaxing break by the coast," she added.
BA will operate the route using an Embraer 190 jet.
