HMAS Penguin is a Royal Australian Navy (RAN) base located at Balmoral on the lower north shore of Sydney Harbour in the suburb of Mosman, New South Wales.

In addition to accommodation for 700 personnel, as well as all the necessary administrative facilities, the Balmoral Naval Hospital was built on the site.

In addition to its role as a depot, Penguin served as a base for the motor launches responsible for patrolling Sydney Harbour.

Penguin has also played host to the RAN Staff College and the Security and Naval Police Coxswains School.

In addition, a number of operational units of the RAN were once based at Penguin, including Clearance Diving Teams One and Two, and the Royal Navy's 4th Submarine Squadron (disbanded 1969).