He was born on 1 November 1831, the son of William Hirst and his wife Sarah (née Kaye), and was baptised on 20 February 1837.
He married Ellen Crowther, daughter of cloth dresser David Crowther and his wife Rachel, in 1853. The couple had two known children:
By 1881, the family was residing at Ash Villa, Lockwood.
William Hirst died aged 77 on 31 October 1909.
Yorkshire Evening Post (01/Nov/1909):
The death has taken place, at his residence, Lockwood, Huddersfield, of Mr. William Hirst, a former member of the Huddersfield Town Council, and a brother of Mr. R. Hirst, an ex-alderman of the borough, and for some time Mayor. Mr. William Hirst began life as a working lad, and with his brother, built up a good business as a cotton manufacturer. He was identified with the Liberal party, and the Baptist denomination at Lockwood.
Leeds Mercury (02/Nov/1909):
Mr. William Hirst, head of the firm of Messrs. William Hirst and Son, cotton spinners and doublers, Turnbridge, Huddersfield, died at his residence, Woodfield, Lockwood, Huddersfield, on Sunday. Mr Hirst, who was 77 years of age, was a Liberal in politics, and had a lifelong connection with Lockwood Baptist Church. For twelve years he was a member of Huddersfield Town Council. He leaves a son and a daughter, both of whom are married. Mrs. Hirst died about three years ago.
Manchester Courier (03/Nov/1909):
The death was announced at Huddersfield, yesterday, of Mr. William Hirst, aged 77, head of the firm of William Hirst & Son, cotton spinners. He started life in a humble way, but along with his brother, the late[sic] Mr. Reuben Hirst, who was twice Mayor of the borough, he worked his way up to a position of affluence.