The Northern Ireland Office will move from Stormont to a new headquarters in the centre of Belfast.
The NIO will join HM Revenue and Customs and the Competitions and Markets Authority officials at the UK government hub at Erskine House on Chichester Street.
The Department of International Trade and Department for Levelling Up, Housing and Communities are also set to move staff to the Belfast hub later this year.
Northern Ireland secretary Brandon Lewis said: “I am delighted that the department will be moving to this fantastic new building in the heart of Belfast city centre.
“Our new workspace will provide a modern working environment that will act as a foundation for the NIO’s work to support the government’s levelling up agenda and make Northern Ireland a better place to live, work and invest.”
The NIO said the move“highlights the department’s desire to become a more accessible, open and modern civil service department” and will allow ministries to collaborate, work in new ways and deliver better services in a safe working environment.
The department said it will also be a good opportunity to increase footfall in the centre of Belfast, boosting the local economy as Northern Ireland recovers from the pandemic.
HMRC permanent secretary Jim Harra welcomed the move, saying the addition of NIO staff to the site would help to “build a professional and vibrant civil service community" in Belfast city centre. HMRC set up an office at Erskine House in January 2020.
Cabinet Office secretary Steve Barclay, who is also the new chief of staff at No.10, said the move will “bring long-term jobs opportunities for people around Belfast”.
He praised the “fantastic work being done in Northern Ireland to ensure that the civil service is deeply rooted in the communities it serves”, calling the relocation an example of “levelling up in action”.
The government published its levelling up white paper, which sets out 12 “missions” to reduce the gap between richer and poorer parts of the UK by 2030, last week.
One of these mission is to “increase pay, employment and productivity in every part of the UK, with each area containing a globally competitive city and the gap between the top performing and other areas closing”.
The government has also committed to moving 22,000 civil service roles out of London by 2030 as part of its Place for Growth programme, with more than 15,000 moves announced already.
The white paper also shows plans to relocate some Cabinet Office roles to Belfast, while the Department for Business, Energy and Industrial Strategy announced last year it would move 60 jobs to the city.