Born in Southwark, Weir was a member of the Streatham Vestry from 1872, and was the representative of the Wandsworth District Board on the Metropolitan Board of Works from 1885. He retired from local government when the Metropolitan Board was abolished and replaced by the London County Council in 1889. He was resident at "The Hawthorns", Grove Road, Clapham Park. He died in February 1902, aged 93, and was buried at Nunhead Cemetery. Grove Road was renamed Weir Road in 1936.