Pjetër Mazreku or Peter Masarechi or Petar Masarechi (1584–16??) (Italian: Pietro Massarecchi, Latin: Petrus Massarecchius) was an Albanian prelate of the Roman Catholic Church.
Born in Prizren from 1624 to 1634 he served as Archbishop of Bar, while in 1631 he became the apostolic visitor of Hungary, Serbia and Slavonia. In 1634 he was ordained as the apostolic administrator of Serbia. From 1642 until his death he served as Bishop of Prizren. He is the author an etymological dictionary of the Albanian language.