Parliament House, Capitol building in Macquarie Street, Sydney, Australia.

Parliament House is a capitol building on Macquarie Street in Sydney, Australia, featuring a two-story Georgian structure with neo-gothic wings. The historic core connects to a modern twelve-story office tower that houses additional parliamentary functions.

The oldest part is the north wing of Governor Macquarie's Rum Hospital, built 1810–1816 with convict labour and funded by a rum-import monopoly; Francis Greenway criticised its construction. In 1829 the Legislative Council began meeting in the former chief surgeon's quarters. A new chamber was added in 1843, and the first bicameral parliament opened on 22 May 1856 in a prefabricated iron building made in Scotland.

The lower house chamber is green, following the House of Commons, while the upper house is red, after the House of Lords. In the red chamber, the vice-regal chair and the president's chair, both of red cedar, date from 1856 and 1886, and seven busts of early presidents and members stand against the bookshelves.

Visitors can participate in one-hour guided tours through the Legislative Chambers and view the historic Parkes, Wentworth, and Jubilee rooms on certain days. It helps to check ahead about availability since tour times vary with parliamentary sessions.

The building was originally planned as a hospital and later repurposed as a parliament, an unusual trajectory for a seat of government. This transformation shapes the spatial layout and heritage character visitors encounter today.