Daniel O'Reilly may refer to:
- Daniel O'Reilly (bishop) (1700–1778), Roman Catholic Bishop of Clogher in Ireland
- Daniel O'Reilly, comedian known under the stage name Dapper Laughs
- Daniel O'Reilly (footballer) (born 1995), Irish soccer player
- Daniel O'Reilly (politician) (1838–1911), Irish-born U.S. Representative from New York, 1879-81