Southern Cross Tower, Skyscraper in Melbourne, Australia.

Southern Cross Tower is a modern skyscraper in Melbourne's business district consisting of two connected sections with glass facades that shimmer in the sunlight. The 39-story structure houses large office spaces primarily used by government departments, with the east tower containing substantial floorspace.

The Victorian Government backed the project to consolidate departments scattered across more than 15 Melbourne CBD office buildings and bring the bureaucracy closer to Spring Street, Parliament and Treasury. A consortium including Multiplex and Babcock & Brown proposed the skyscraper on the site of the derelict Southern Cross Hotel, and the government required an environmentally sustainable development. The tower was completed in 2004.

The tower stands on the site of the old Southern Cross Hotel, a landmark of Melbourne's mid-20th-century hotel scene. Its main tenant is the Victorian State Government: SX1 houses the Department of Justice and Regulation, parts of the Department of Jobs, Precincts and Regions, and the State Revenue Office, while SX2 holds Australia Post and the Energy and Water Ombudsman (Victoria).

Southern Cross Tower stands at 121 Exhibition Street, between the central business district and the Parliament and Treasury precinct on Spring Street. The complex is split into SX1, the 39-level east tower, and SX2, the 22-level west tower. The building is not open to the public; the offices are tenanted by Victorian government departments, Australia Post and the Energy and Water Ombudsman.

The site was previously occupied by the Southern Cross Hotel, a prestigious Melbourne establishment that was demolished to make way for the tower. The Victorian Government required the new development to be environmentally sustainable, and the building is now 75 per cent owned by Multiplex Property Trust and 25 per cent by Multiplex Acumen Prime Property Fund.