Joseph Alexander Gillies (September 17, 1849 – July 7, 1921) was a Canadian politician. Born in Irish Cove, Nova Scotia, the son of John Gillies and Mary McLean, Gillies was educated at St. Francis Xavier University graduating in April 1871. He was called to the Nova Scotia bar in 1875 and practised law in Sydney. He was the registrar of probate for the County of Cape Breton, Nova Scotia from August 1872 until he resigned when he ran unsuccessfully for the riding of Cape Breton in the 1887 federal election. He was clerk of the Peace for Cape Breton county from December 1875 until January 1880 when the county was incorporated, and then he was appointed Municipal clerk, which he held until January 1883 when he became solicitor of the municipality (Sydney).