The Princess Theatre, originally Princess's Theatre, is a 1452-seat theatre in Melbourne, Victoria, Australia. Established in 1854 and rebuilt in 1886 to a design by noted Melbourne architect William Pitt, it is the oldest surviving entertainment site on mainland Australia. Built in an elaborate Second Empire style, it reflects the opulence of the "Marvellous Melbourne" boom period, and had a number of innovative features, including state of the art electric stage lighting and the world's first sliding ceiling, which was rolled back on warm nights to give the effect of an open-air theatre.