Cardiff's Coal Exchange hotel is set to reopen in October after its manager allayed concerns over noise at night affecting neighbours.
The historic building's future was in doubt when owners Signature Living went into administration in May.
Eden Grove, which now manages the premises in Butetown, said a 03:00 licence was needed to earn money to pay creditors and keep people in jobs.
Cardiff councillors backed the licence with conditions to keep noise down.
Built in the 1880s, the Coal Exchange became a hub of global trade in Cardiff's docklands before closing in 1958.
Since then, it has been used for live music and other events before being refurbished and reopening as a hotel in 2017.
The licensing committee heard that Eden Grove had committed to hosting 46 weddings which were booked before the collapse of Signature Living, despite not receiving the money that couples paid to the previous company.
On the question of noise, hotel manager Brian Gamble said regular decibel readings would be taken by hotel staff during evening events to help keep the noise down.
"It's not in our interest to continue with sound levels that would upset our own internal residents," he said.
"You're always better having your residents on side, rather than against you."
To help keep the noise down, the licence restricts the hotel from emptying bottle bins after 20:00.
Revellers will also be asked to not take their drinks outside after that time, according to the Local Democracy Reporting Service.