Crumlin Road Courthouse is to be transformed into a £25 million luxury hotel.
The landmark heritage building dating from 1850 has fallen into a state of disrepair and the Signature Living Group said it planned to restore it to its former glory.
It will be the first of up to five new hotels the developer will bring to the city over the next three years.
Signature chairman Lawrence Kenwright said "The courthouse is currently in a state of disrepair and our focus will be on sympathetically restoring the building to its former glory in a way that is both true to its architectural heritage and aligns with the exciting style for which Signature Living is reputed.
"We see ourselves simply as custodians of these important buildings and the courthouse will very much still belong to the people of Belfast.
"For us, this is an investment in the local Belfast community and, as well committing around £25 million to the restoration project, we will be investing in a series of community initiatives - including the launch of a special apprenticeship academy - in the coming months."
The courthouse was designed by Sir Charles Lanyon.
Inside its imposing edifice the gruesome crimes of the Shankill Butchers were investigated in forensic detail and the supergrass trials were the largest in British criminal history.
In 1983 22 IRA suspects were jailed for a total of 4,000 years.
It was once linked by a tunnel with Crumlin Road Gaol.
The Gaol has been turned into a tourist attraction.
Belfast City Council Chief Executive Suzanne Wylie said a surge in tourism in Belfast in recent years required over 2,000 additional beds.
"So this hotel is good news for the city and complements steps being taken to continuing driving a growth in visitor numbers to the city through initiatives such as the IRFU Rugby World Cup 2023 bid and the European Capital of Culture 2023 bid."