长瓣兜兰（学名：Paphiopedilum dianthum）为兰科兜兰属下的一个种。

Paphiopedilum dianthum is a species of flowering plant in the orchid family, Orchidaceae. It is native to China, Laos, and Vietnam. It is known commonly as the double flowered paphiopedilum.

This species grows on limestone in forest habitat. It produces 4 to 6 green leathery leaves. It bears 1 to 5 flowers at the top of an erect or arching stalk up to 80 centimeters long. The flower is up to 10 centimeters wide. The dorsal sepal is white with green veining and the synsepal is greenish to yellow-green with green veining. The striped greenish or brownish lateral petals are long and twisted with hairy warts. The lip is helmet-shaped.