Robert Stanley Welch (died 2000) was a Canadian politician.

Welch was a member of the St. Catherines, Ontario Board of Education from 1955 until his election to the Ontario legislature in 1963 as the Progressive Conservative MPP for Lincoln (he moved to the neighbouring riding of Brock in the 1975 Ontario election). In 1966 he was appointed to the cabinet of Ontario Premier John Robarts as Provincial Secretary and Minister of Citizenship.

When Robarts retired, Welch ran to succeed him and placed fourth in the 1971 Ontario Progressive Conservative leadership convention.

Welch served in a variety of cabinet positions under new Premier Bill Davis. Generally, he was used as a "fixer" and placed temporarily in politically difficult portfolios as a crisis manager.

He was Minister of Education from 1971 until 1972 and then served as provincial secretary for Social Development and Minister of Housing until 1974 and then Attorney-General until 1975. He was Minister of Culture and Recreation from 1975 until 1978 and then Provincial Secretary for Justice until 1979. He then served as Minister of Energy from 1979 until 1983. As well, Welch was deputy premier from 1977 until he left politics in 1985. When Frank Miller succeeded Davis he made Welch his Attorney General, Deputy Premier and Government House Leader. Welch did not run in the 1985 Ontario election and retired from politics.

Welch served as chancellor of Brock University from 1985 until his death in 2000.