Twice-weekly Manchester-Murcia flights will take off on 2 May 2023, while Belfast International will gain a new twice-weekly Rhodes route starting 3 June 2023.
Both sets of flights will operate on Tuesdays and Saturdays. Fares go on sale on 7 December.
The carrier will base a 21st aircraft at Manchester and an eighth at Belfast, with each addition creating 35-40 new jobs locally.
Both new based aircraft are 186-seat Airbus A320neos, which offer 15% less fuel burn and up to 50% noise reduction during take-off and landing.