Guy Willy Razanamasy (19 December 1928 – 18 May 2011) was a Malagasy politician who served as Prime Minister of Madagascar from 1991 to 1993. Born in Antananarivo, Razanamasy worked as a pharmacist and drug manufacturer before becoming the director of pharmacological society of "cofarma" and entering politics. He was elected Mayor of Antananarivo in the 1980s. In 1994, Razanamasy again became Mayor of Antananarivo, serving out his five-year term. He stood in the 1996 presidential election as the candidate of the , but took only 1.2% of the total votes cast and was eliminated in the first round.