James Gillespie Barclay (1882–1972) was a New Zealand politician of the Labour Party. He was a cabinet minister in the First Labour Government from 1941 to 1943; Minister of Agriculture and Minister of Marketing, and in 1943 Minister of Lands also.
He represented the electorate of Marsden in Northland from the 1935 general election but was defeated in 1943.
He then became High Commissioner to Australia from 1944 to 1950
A son, Bruce Barclay, was Member of Parliament for Christchurch Central from 1969 to 1979. A relative, Ron Barclay, was also an MP.