Diarmuid O'Sullivan is an Irish hurling coach and hurler who plays for Cork Premier Championship club Cloyne. He played for the Cork senior hurling team for 12 years, during which time he usually lined out as a full-back. A fan favourite who was noted for his swashbuckling style during his inter-county career, O'Sullivan is considered a "Cork legend".

The National Hurling League is an annual inter-county hurling competition featuring teams from Ireland and England. Founded in 1925 by the Gaelic Athletic Association, it operates on a system of promotion and relegation within the league system.