The Shoalwater Islands Marine Park is a protected marine park located in Western Australia and stretches from the northern point of the Garden Island Causeway to the southern point of Becher Point. The 6540 ha marine park is located offshore from the suburban locality of Shoalwater. Several small limestone islands are located within the boundaries of the marine park, but not part of it, including Seal Island, which is part of the Shoalwater Bay Islands Nature Reserve, and Penguin Island, which is part of the Penguin Island Conservation Park.