Bantry Bay is a bay located in County Cork, southwest Ireland. The bay runs approximately 35 km (22 miles) from northeast to southwest into the Atlantic Ocean.

It is approximately 3-to-4 km (1.8-to-2.5 miles) wide at the head and 10 km (6 miles) wide at the entrance.

Main routes that follow parts of the bay include the R572 (part of the "Ring of Beara") and the N71. The Bantry Bay Golf Club is at the head of the bay, across from Whiddy Island. The O'Sullivan Beara Castle Dunboy is just across from Bere Island. "Copper John" Puxley's Manor is in Dunboy.