Patrick Duncan McTaggart-Cowan, OC MBE (May 31, 1912 – October 11, 1997) was a Canadian meteorologist and the first president of Simon Fraser University.

Born in Edinburgh, Scotland, he moved to North Vancouver, British Columbia, Canada with his family in 1913.

A Rhodes Scholar, he received a Bachelor of Arts in Natural Science from Corpus Christi College, Oxford in 1936.

During World War II, he was the chief meteorologist for the RAF Ferry Command and was made a Member of the Order of the British Empire in 1944.

His brother was the naturalist Ian McTaggart-Cowan, and his sister the architect Pamela Charlesworth.