The Gulf of Patras (, Patraikós Kólpos) is a branch of the Ionian Sea. On the east, it is closed by the Strait of Rion between capes Rio, Greece and Antirrio, near the Rio-Antirio bridge, that is the entrance of the Gulf of Corinth  On the west, it is bounded by a line from Oxeia island to Cape Araxos. To the north it is bounded by the shore of Aetolia-Acarnania in continental Greece, and to the south by Achaea in the Peloponnese peninsula. It is 40–50 km long, 10–20 km wide, and has an area of 350–400 km².