James "Jimmy" Halliday (27 February 1927 - 3 January 2013) was a Scottish author, historian and politician. He was the chairman (leader) of the Scottish National Party (SNP) from 1956 to 1960.Halliday was born in Woodburn Cottage, Wemyss Bay, Renfrewshire, the son of James Wightman Halliday, an estate gardener. Halliday was educated at Skelmorlie Primary School and Greenock Academy. He joined the SNP in 1943, aged 16, and also registered for military service in World War II.