Radu Marian (Romanian pronunciation: [ˈradu mariˈan]; born 1977) is a Moldovan male soprano (sopranist).

He possesses a pure soprano voice in the range of C4 to C6, and he is considered an important singer in Baroque music. His repertoire incorporates cantatas written for soprano by composers like Händel, Bononcini, Carissimi, and Frescobaldi, and the repertoire of the old castrati. He has been called "the Baroque nightingale" by the Italian newspaper Corriere della Sera.

Marian is an "endocrinological castrato" or "natural castrato". A natural castrato is a male singer who never went through puberty and is able to keep his "unbroken" voice intact without castration.