Bionnus or Bionnos () was a town and polis (city-state) of ancient Crete. It is known from epigraphic evidence. Bionnus is mentioned in a list of theorodokoi of Delphi, dated between 230 and 210 BCE, between the cities of Psycheion and Matala.
The site of Bionnus is located near modern Pyrgos ('high ground'), about south of Kerames.