The Regal Theatre, formerly known as the Chelsea Cinema, the Princess Theatre and the Ozone Marryatville or Marryatville Ozone Theatre, is a single-screen cinema in Kensington Park, a suburb of Adelaide, South Australia. Originally built in 1925, it retains the features of a major renovation in Art Deco style in 1941, and was heritage-listed on the state register in 1983. It is the oldest continuously running purpose-built cinema in Adelaide, and the only remaining silent cinema still operating.