Robert Milton Cato (June 3 1915 February 10 1997) was a socialist political leader in Saint Vincent and the Grenadines.

Cato was born on Saint Vincent island. He joined the Canadian army and was involved in battles during World War II. After returning to saint Vincent, he became involved in local politics. In 1955 he co-founded the Saint Vincent Labour Party, also known as the Unity Labour Party. In 1967, when Saint Vincent and the Grenadines became an associated state, he became chief minister. He became Prime Minister in 1969.

Cato lost elections in April 1972 and the opposition lader, James Fitz-Allen Mitchell became Prime Minister. Cato's party and its coalition partners won elections in 1974. He served as Prime Minister again from 1974 until 1984, even though his coalition collapsed during the mid 1970s. Cato led his country to complete independence from Britain in 1979. Cato's government did not support other nearby socialist governments such as those in Cuba, Grenada and Guyana as he opposed Marxism. Instead, he allied with more conservative governments such as those in Trinidad and Tobago and Barbados, cooperating with them on economic and defense matters.

The Labour Party lost elections in 1984. It is still one of the two main political parties in Saint Vincent and the Grenadines. It returned to power in 2001 under Ralph Gonsalves. Cato died in Kingstown, Saint Vincent.