Pilosocereus robinii is a species of cactus known by the common name Key tree-cactus. It is native to the Florida Keys in the United States. It may occur in Cuba, but any populations there are unconfirmed. It has been reported from Puerto Rico, the Virgin Islands, and Mexico. It is a rare species which is threatened by the loss of its habitat. It is a federally listed endangered species of the United States.