John Street Marina (Pier 21 Marina) is a 165-berth boat marina situated on the Swan River in North Fremantle. It caters for medium and large-scale pleasure craft and some commercial boats.

The Lester Group owned the riverbed lease and marina, and operated the marina until its sale in August 2008. 46 of the berths are allocated to owners of The Moorings residential apartments so that each resident enjoys direct access to their own boat moored at the end of their garden.