Alexander Hay (8 January 1865 – 8 May 1941) was a New Zealand-born Australian politician.
Born in Auckland, New Zealand, he was educated there at Auckland Grammar School. Upon inheriting estates in Queensland, he migrated to Australia in 1893, becoming a grazier in New South Wales.
In the first federal election, he unsuccessfully contested the seat of Illawarra as a Protectionist; in 1914 he contested Hunter (again unsuccessfully) as a Liberal. In 1919, he was elected to the House of Representatives as a Nationalist, representing the seat of New England. He had also been endorsed by the Farmers and Settlers' Association, and joined the Country Party when it was formed in 1920. His tendency to vote against his party resulted in his expulsion in 1922. He contested the election of that year as an independent but was unsuccessful. He retired from politics and returned to farming, dying in 1941.