Ralph Desmond Clarke (born 4 October 1951) is a former Australian politician. He was a Labor Party member of the South Australian House of Assembly between 1993 and 2002, representing the electorate of Ross Smith. He was the deputy leader of the State Parliamentary Labor Party, and thus the deputy opposition leader, until he was deposed in factional infighting. Clarke contested an upper house seat under a banner of "Buy back ETSA" at the 2006 election but failed with only 0.1% of the vote, only 1115 votes. In October 2007 Clarke was elected as an Area Councillor for the City of Adelaide.