Donlevy is a surname of Irish origin. Also spelt as MacDonlevy, Donleavy, Dunleavy, and MacAleavey, it derives from the Irish Mac Duinnshléibhe, meaning "brown mountain". Ó Duinnshléibhe is a variant Irish spelling. Their eponymous ancestor is Donn Sléibe mac Echdacha, who ruled as king of the Irish petty-kingdom of Dál Fiatach, as well as its over-kingdom, Ulaid, in the late 10th century. In the aftermath of John de Courcy's conquest of Ulaid in 1177, some of the dynasty migrated to present-day County Donegal in the Republic of Ireland, whilst others went to Scotland. In Donegal they became the hereditary physicians of the Cenél Conaill of Tír Conaill.
After the Battle of Kinsale in 1602, the sept migrated to the province of Connacht, where their name is now most common. Some MacDonlevy's in Donegal adopted the surname Mac an Ultaigh, meaning "son of the Ulsterman", which was anglicised as MacAnulty and MacNulty.
- Andrew Donlevy (1694-), Irish Roman Catholic priest.
- Brian Donlevy (1889–1972), Irish born American actor.
- Cormac MacDonlevy (fl. c. 1460), influential medieval Irish physician and medical scholar
- Frank Donlevy (b. 1932), Scottish footballer
- Chris Dunleavy (born 1949), English footballer
- Dan Dunleavy, Canadian sportscaster
- Jack Dunleavy (1879–1944), American baseball player
- John Dunleavy (born 1991), Irish footballer
- Patrick Dunleavy (born 1952), political scientist
- Mary Dunleavy, American opera singer
- Mike Dunleavy, Sr. (born 1954), former NBA coach and former NBA player
- Mike Dunleavy, Jr. (born 1980), NBA forward and former Duke Blue Devil; son of Mike Dunleavy Sr.
- Mike J. Dunleavy (born 1961), American politician, member of the Alaska Senate since 2013
- Philip Dunleavy (1915–1996), Welsh politician
- Richard Dunleavy (born 1933), US naval officer
- Rosemary Dunleavy, American ballerina
- Steve Dunleavy (born 1938), a US-based Australian-born journalist
- Cormac Mac Duinnshléibhe, a fifteenth-century Irish physician and scribe
- Suibhne mac Duinnshléibhe, a thirteenth-century Scottish magnate
- Donnchadh mac Eoghan Ó Duinnshléibhe, d. 1528.
- Muiris mac Donnchadh Ulltach Ó Duinnshléibhe, Irish cleric, fl. 1602–1630's
- Muiris mac Seaán Ulltach Ó Duinnshléibhe, Irish cleric, fl. 1602–1630's.
List of Mac Duinn Sléibe kings of Ulaid
- Donn Sléibe mac Eochada 1081–1091, the eponymous ancestor of the Mac Duinn Sléibe dynasty.
- Donnchad mac Duinn Sléibe 1091–1095
- Eochaid mac Duinn Sléibe 1095–1099
- Donnchad mac Duinn Sléibe 1099–1099
- Eochaid mac Duinn Sléibe 1099–1108
- Donnchad mac Duinn Sléibe 1108–1113
- Áed mac Duinn Sléibe 1113–1127
- Cú Ulad mac Conchobair Chisenaig Mac Duinn Sléibe 1131–1157
- Áed mac Con Ulad Mac Duinn Sléibe 1157–1158
- Eochaid mac Con Ulad Mac Duinn Sléibe 1158–1166
- Magnus mac Con Ulad Mac Duinn Sléibe 1166–1171
- Donn Sléibe mac Con Ulad Mac Duinn Sléibe 1171–1172
- Ruaidrí mac Con Ulad Mac Duinn Sléibe 1172–1201
- Cu-Ulahd Mac Duinn Sléibe (fl. c. 1178)
- Bell, Robert (2003). The Book of Ulster Surnames. The Blackstaff Press. ISBN 978-0-85640-602-7.
- Keating, Geoffrey (1983). Keating's History of Ireland. Irish Genealogical Foundation. ISBN 978-0-686-44360-5.