Sir Horace Rostill Petty (25 March 1904 – 16 February 1982) was an Australian politician.
He was born in Richmond to wool block engraver Frederick Charles Petty and Alice Maud Rostill. He attended University High School and then the University of Melbourne, where he received a Bachelor of Commerce. On 22 February 1930 he married Mary Margaret Anastasia Watt. He worked for the Argus as a circulation manager, and during World War II served with the AIF. After the war he became a newsagent at Toorak; he was also an early member of the Liberal Party, and served on Prahran City Council from 1949 to 1964 (as mayor from 1951 to 1952). In 1952 he was elected to the Victorian Legislative Assembly as the Liberal and Country Party member for Toorak. In 1955 he was appointed Minister for Housing, adding Immigration the following year; he exchanged Housing for Public Works in 1961. In 1964 he retired from politics, and was given a knighthood. On 2 November 1959 he had married Beryl Anne Hoelter, with whom he had four children. Petty died in Richmond in 1982.
|Victorian Legislative Assembly|
| Member for Toorak