Breakwater Battery, was a coastal defence battery at Port Kembla, New South Wales, Australia during World War II.

Constructed in 1939 to provide protection for Port Kembla from enemy shipping and submarines. Two 6 inch Mk XI gun emplacements with related underground facilities were constructed near the southern breakwater at Port Kembla.

The battery and observation post (now a military museum) were key structures of the command centre for Fortress Kembla during World War II.