Customers can book flights from Belfast to Birmingham, Edinburgh, Leeds Bradford, Manchester, Glasgow, and Exeter.
With fares from £36.99, the first phase will commence on 24 March with a three-times weekly service to Birmingham and twice-weekly services to Edinburgh and Leeds Bradford. A three-times weekly route to Manchester will begin on 27 March.
Daily services from Belfast to Glasgow and a five-times weekly route to Exeter will start in early May.
Conor McCarthy, chief executive of Emerald Airlines, said the carrier wants to be "the airline of choice" for customers travelling to and from Belfast.
"Having already announced our services linking Belfast to Manchester, Birmingham, Glasgow, Edinburgh, Leeds Bradford and Exeter, we are delighted to go on sale from today with Aer Lingus and British Airways," he added.
"We’re keen to build upon our announcement today, with more flights, destinations, and great fares to follow in the very near future."
The new routes are the result of a long-term partnership between Belfast airport and Emerald Airlines. Aer Lingus and BA services to London City airport and Heathrow from Belfast remain unchanged.
