Dorgan (Ó Deargáin) is an Irish surname, derived from dearg "red" (compare Craoibh Dearg). Notable people with the surname include:

• Byron Dorgan (born 1942), United States senator from North Dakota
• Howard Dorgan (1932–2012), American academic known for his research and writing on religion in Appalachia
• Jerry Dorgan (1856–1891), American baseball player
• Jim Dorgan (born 1930), Australian rules football player
• John L. Dorgan (born 1879), known as Ike Dorgan, American boxing manager, and publicity manager for the Madison Square Garden, founding partner of The Ring magazine
• Joseph "Joe" Dorgan (born 1975), American professional wrestler and personal trainer, best known as Johnny Swinger
• Mike Dorgan (1853–1909), American baseball player
• Patrick Dorgan, Danish singer
• Richard W. Dorgan (1892–1953), American cartoonist
• Seán Dorgan (born 1968), Irish politician
• Tad Dorgan (1877–1929), American cartoonist
• Theo Dorgan (born 1953), Irish poet, writer and lecturer

See also

• Dorgon (1612–1650), Qing dynasty regent
• Morgan Dangerfield and Donavon Cavanaugh the formidable duo of Veterinary Consultants combine to form what has come to be known as the “Dorgan”