Patrick O'Boyle was born in Scranton, Pennsylvania, to Michael and Mary (née Muldoon) O'Boyle, who were Irish immigrants. His father was originally from County Sligo, and in 1889 came to the United States, where he settled at Bedford, New York. His mother moved to New York City from County Mayo in 1879, and later married O'Boyle in December 1893. Shortly afterwards they moved to Scranton, where Michael became a steelworker; they had a daughter who died during infancy in 1895.