Gregory Reinhart (born June 18, 1951 in Pavilion, New York) is an American bass opera singer. He is noted for an extremely wide repertory which ranges from early music to the world premieres of several contemporary operas including Lowell Liebermann's The Picture of Dorian Gray, Philippe Manoury's K..., and Pascal Dusapin's Perelà, uomo di fumo.

He has been praised in The Metropolitan Opera Guide to Recorded Opera for his performance in Monteverdi's L'Incoronazione di Poppea as one of the finest Senecas on record with "a magnificent bass voice: firm and clear throughout its wide range".