Clark Island was named after a marine officer, Lieutenant Ralph Clark, who arrived in 1788 with the First Fleet.

In 1789, Lieutenant Clark tried to cultivate a vegetable garden on this one hectare island. He abandoned the idea when his crops were repeatedly stolen; ever since, the island has been known by his name. Today small groups use Clark Island as a picnic area. Facilities include drinking water, picnic tables and toilets.

The number of people is restricted to 30 per group with a maximum island capacity of 150 people. The island is also available for wedding ceremonies and exclusive hire (additional fees and conditions apply).