The island is 1.5 kilometres (1 mi) offshore from Cheynes Beach and is a protected area managed by the Department of Parks and Wildlife.

Composed almost entirely of granite the island rises steeply from the ocean to a maximum height of 310 metres (1,017 ft).

More exposed areas are covered by open heath and tussock species, as well as closed shrubby patches mostly comprising Melaleuca microphylla.

One of the species of skink, Ctenotus labillardieri, has evolved into a distinctive insular race on the island.

Marine mammals such as New Zealand fur seals and Australian sea lions inhabit Bald Island.