Sinus or Sinos (Ancient Greek: Σίνος) was a town of the Chalcidice in ancient Macedonia.
It belonged to the Delian League since it appears in the tribute records of Athens of 434/3 and 433/2 BCE, where it paid a phoros of 1500 drachmas, and in those of 421/0 BCE where it paid 800 drachmas.
It also appears in a tributary decree of 422/1 BCE.
[1] Its territory was probably the Sinea found in an inscription dated to 305-297 BCE.
This article about a location in ancient Macedonia is a stub.