Joseph Cassidy was born in Kilmarnock in 1869. He played for Glasgow Hibernian before joining Bolton Wanderers in 1889.

In only his fifth game he scored four goals in a 7-1 win over Derby County. In a 2nd round FA Cup tie Cassidy scored five goals in Bolton's record 13-0 win over Sheffield United. He ended that season as the club's leading scorer with 20 goals in 19 games.

Cassidy played in Bolton's first game at Burden Park and scored one of the goals in the club's 3-1 victory over Everton.

Cassidy played for Bolton Wanderers for eight seasons. He was the club's top scorer in five seasons and overall he scored 101 goals in 219 games. The record books show he retired from professional football in 1897.