The incident happened outside Belfast City Hall on Donegall Square North shortly before 2am.
A 19-year-old man has been arrested and is in police custody.
The victim has been taken to hospital for injuries which are being described as serious.
Detective Sergeant Corrigan said: “I would appeal to anyone who was in the area of Donegall Square North just before 2.00am this morning or anyone who has dash-cam footage of this incident to contact Detectives at Musgrave on the non-emergency number 101, quoting reference 122 10/11/18.”
Alternatively the public can contact independent charity Crimestoppes anonymously on 0800 555 111.