Supayacetus (after Supay, the Incan god of death, and ketos Greek for whale) is an extinct genus of basilosaurid cetacean from Middle Eocene (Bartonian stage) deposits of southern Peru. Supayacetus is known from the holotype MUSM 1465, a partial skeleton. It was collected in the Archaeocete Valley site, from the Paracas Formation of the Pisco Basin about 37 million years ago. It was named by and the type species S. muizoni honours palaeontologist Christian de Muizon who has contributed considerably to Peruvian palaeontology.