Three of its newest domestic routes – Exeter, Glasgow and Leeds from Belfast have been extended while customers will also be able to book direct to Birmingham.
Customers can now book on BA.com for travel between 31 October 2021 and 26 March 2022.
The extended routes will continue to link Northern Ireland and key cities across the UK following a successful summer, BA says.
Flights between Belfast and Birmingham will operate twice daily, increasing to three times a day on Thursdays and Fridays to meet demand for long weekends.
Flights from Belfast to Exeter, Glasgow and Leeds will increase at four, 13 and 10 a week respectively.
Tom Stoddart, Managing Director of BA CityFlyer which operates the routes, said: “This year has shown how much customers want to stay connected with the rest of the UK. We’re responding to the customer demand we saw over the last few months by extending some of our newest UK routes from Belfast City Airport.”