He was born in Parkes to farmer John Patrick McGirr and Mary O'Sullivan, and was educated at St. Joseph's Convent.
He left school at a young age to work in shearing sheds, funding the education of his brothers and future parliamentarians, James and Greg; he also became an active member of the Australian Workers' Union.
He later became a successful businessman, dealing in cattle and owning a number of pastoral estates in the Forbes area, including at various times the Grawlin, Ralrida and Bundaburra estates, while also acquiring substantial property and business interests in Forbes township.
He was narrowly defeated in 1920 running for the multi-member seat of Murrumbidgee, but in 1921 he was appointed to the New South Wales Legislative Council, in which he served until his retirement in 1955.
This article about an Australian Labor Party member of the Parliament of New South Wales is a stub.