Willie was Pádraig's younger brother. He was educated at the Christian Brothers' School, Westland Row, Dublin. A talented scluptor, he obtained a distinction in the Metropolitan School of Art and studied in Paris. He was also a talented actor and appeared in many productions at the Irish Theatre in Hardwicke Street. He founded St Enda's School in Ranelagh with his brother in 1908. He was a captain in the GPO during the Easter Rising. It has been said that the role he played was a minor one. However, Willie did not downplay his role at his court martial, and may well have signed his own death warrant. He was executed on the 4 May, one day after his brother Pádraig.