Morahan is an Irish surname, from the Irish Ó Murcháin, meaning 'sea-warrior'. Notable people with the surname include:
Andy Morahan (born 1958), English commercial, film and music video director Caroline Morahan (born 1977), Irish actress and television host Christopher Morahan (born 1929), English stage and television director and producing manager Edythe Morahan de Lauzon, Canadian poet Eugene Morahan (1869–1949), American sculptor Hattie Morahan (born 1978), English television, film and stage actress Jim Morahan (1902–1976), British art director Luke Morahan (born 1990), Australian Rugby Union Player Thomas Morahan (1931–2010), member of the New York State Senate Thomas N. Morahan (1906–1969), British film designer