Ultimo is a suburb in central Sydney, New South Wales, Australia. 'Ultimo' was originally the name of the estate of John Harris which occupied the area - it was named for a clerical error in a legal case against him that had prevented him being cout-martialled, due to his offence having been listed as 'ultimo', having occurred in the previous month, when it should have been cited as 'instant', having occurred in the same month [1].

Ultimo is home to the main campus of the University of Technology, Sydney and the largest TAFE in New South Wales, both located on Ultimo’s southern boundary. The Sydney-based radio and television studios for the Australian Broadcasting Corporation are also located in Ultimo on the thoroughfare of Harris Street . Harris Street is also the home of Sydney's Powerhouse Museum. The Ultimo portion of Broadway, which experienced considerable redevelopment during 2004, is becoming increasingly vibrant.

Located adjacent to the Sydney CBD, Ultimo is well-served by public transport. Central railway station is at the southern border of the suburb, on the opposite side of Broadway. Metro Light Rail and the Sydney monorail both have stations at the eastern edge of the suburb, where Ultimo borders Darling Harbour. Many buses travel along Broadway.

Its proximity to Chinatown means that it has historically had a large Chinese population.