Brown Island, Brown's Island, or Browns Island may refer to:

Brown Island or Brown Atoll, the Japanese name for Enewetak Atoll

Brown Island (Antarctica)

Browns Island (New Zealand), a small volcano off the coast of Auckland

Browns Island (California), a 595-acre (2.41 km2) wetland in the San Jaoquin-Sacramento Delta

Brown Island (Massachusetts)

Brown Island (New York), an island on the West Canada Creek

Brown Island (North Carolina), a barrier island located near Marine Corps Base Camp Lejeune

Brown's Island, Virginia

Brown Island (Washington)

Browns Island (Washington), and island in the Columbia River, west of Wishram, Washington

Browns Island (West Virginia), an island in the Ohio River

Tahoramaurea Island / Browns Island, an island in the Wellington region of New Zealand