Denis J. O'Connell was an Irish-born American prelate of the Roman Catholic Church. He served as bishop of the Diocese of Richmond in Virginia from 1912 to 1926. He previously served as an auxiliary bishop of the Archdiocese of San Francisco in California from 1908 to 1912.

The Diocese of Richmond is a Latin Church ecclesiastical jurisdiction, or diocese, of the Catholic Church in Virginia in the United States. It is a suffragan diocese of the metropolitan Archdiocese of Baltimore.