[1]: 18 Bedout is a low and undulating, 31-hectare (77-acre) sandy cay on limestone bedrock, heavily vegetated with beach spinifex.

It has an arid climate, an annual average rainfall of 300 millimetres (12 in), and experiences occasional tropical cyclones.

At some time in the past black rats were inadvertently introduced, probably by visiting pearling vessels in the late 19th century, but were eradicated in 1991.

[4] The island supports over 1,000 nesting pairs of brown boobies, making it one of the largest colonies in Western Australia.

[5] Bedout Island is also home to over 1,000 nesting pairs each of common noddies and crested terns, 500–1,000 lesser frigatebirds, 100–500 masked boobies, as well as lesser crested, roseate and sooty terns, silver gulls and white-bellied sea eagles.