Peter (Petrus) Hasse (ca. 1585 – 1640) was a German organist and composer, and member of the prominent musical Hasse family. The first written record of Hasse dates from his appointment as organist at the Marienkirche in Lübeck, a post later held by Buxtehude. Although literally nothing is known of Hasse's early life, he is believed to have been a student of Sweelinck between 1606 and 1609. Hasse remained in Lübeck until his death in 1640, and achieved considerable fame at the time as a teacher and performer. His son, Nikolaus Hasse, was among his pupils, and became a musician in his own right. Hasse's own surviving output is small, consisting of just three organ works and two choral works.