Masashi Hamauzu (浜渦正志, Hamauzu Masashi, born September 20, 1971) is a Japanese composer, pianist, and lyricist. Hamauzu, who was employed at Square Enix from 1996 to 2010, was best known during that time for his work on the Final Fantasy and SaGa video game series. Born into a musical family in Germany, Hamauzu was raised in Japan. He became interested in music while in kindergarten, and took piano lessons from his parents.

Hamauzu was hired by Square as a trainee, and his debut as a solo composer came the following year when he scored Chocobo's Mysterious Dungeon. He has collaborated with friend and fellow composer Junya Nakano on several games.

After Nobuo Uematsu left Square Enix in 2004, Hamauzu took over as the leading composer of the company's music team. He was the sole composer for Final Fantasy XIII. He has also become a renowned pianist, arranging for several other composers. His music incorporates various styles, although he often uses classical and ambience in his pieces. In 2010, Hamauzu left Square Enix to start his own studio, MONOMUSIK.