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