On the corner of Collins and King Street stood Robb's Buildings, named for the owner, railway builder John Robb, a grand classical styled 5-storey Victorian office building designed by Thomas Watts and Sons[3] in 1885, and one of the largest in the city at the time.

Little progress was made until 1980 when the site was acquired by Grollo Australia in a joint venture with St Martin's Properties.

The final development plan involved several separate projects proceeding concurrently: the 242m office tower; a five-level underground car park; the restoration of the historic Rialto and Winfield building to create an international hotel; and a theatrette.

Ancillary works included the Collins Street Plaza, restoration of the York Butter Factory and Robbs Annexe, and new shops.

Designed by architects Gerard de Preu and Partners in association with Perrott Lyon Mathieson, the building was built between 1982 and 1986, opening in October 1986.

[8] The Melbourne Observation Deck opened to the public on 19 July 1994 and was located on the 55th floor of the South Tower, at 234 m (768 ft).

[9] In 2015–17, the partly roofed, partly open forecourt-podium was replaced with a 5 level perimeter building containing offices, with retail at ground level, and an internal glass-roofed area between it, the towers, and the side wall of the original Victorian era Rialto building.

When completed in 1986, The Rialto surpassed Sydney's MLC Centre to become Australia's tallest building at 251 m (823 ft).