Brook Islands National Park, Nature reserve in Cassowary Coast Regional, Australia.

Brook Islands National Park covers 0.9 km² across North, Tween and Middle islands, lying 7 km north-east of Cape Richards on Hinchinbrook Island and 30 km east of Cardwell. North Island, the largest, holds notophyll vine forest with dense stands of the rare palm Arenga australasica and golden orchids Dendrobium discolor on shoreline rocks. The islands have no roads, tracks or facilities, and landing is prohibited to protect breeding birds.

In 1944, North Brook Island hosted British and American tests on the military use of mustard gas. Pits were dug and Japanese-style dugouts built for the trials; almost no trace remains. Film Australia released a documentary on these tests in 1989.

The islands serve as a crucial refuge for migratory birds that move between mainland feeding areas and their nesting grounds. Visitors observe from a distance how these populations depend on this protected space for their survival.

The three park islands are closed to landing, and there are no roads, tracks or facilities. Boating, snorkelling and fishing are allowed in the surrounding waters. The islands lie 7 km north-east of Cape Richards on Hinchinbrook Island and 30 km east of Cardwell.

Up to 60,000 pied imperial-pigeons breed on the three islands each summer, flying out to feed on rainforest fruits on the mainland and Hinchinbrook Island and returning to their nests at dusk. BirdLife International lists the group as an Important Bird Area for this species and for lesser crested terns, which also nest here.