Phu Ruea (Thai: ภูเรือ), is a 1365 m high mountain in Loei Province, Thailand. It is in Phu Ruea District. This mountain is part of the Phetchabun Mountains, a mass is forming a natural boundary between northern Thailand and Isan. The peak rises seven kilometers north of Highway 203, between Loei town and Phetchabun. The name of the mountain comes from the fact that it looks like a boat (Thai: เรือ) upside down from certain angles.
The Phu Ruea High Altitude Agricultural Research Station and Phu Ruea National Park are in the area around the mountain. The park borders Sainyabuli Province in Laos at its northern end. Most of the mountain is covered in mixed evergreen forest. The area around the mountain is part of the Luang Prabang montane rain forests ecoregion.
The government split off some parts of Tha Li, Mueang Loei, and Dan Sai Districts and made them into the minor district (king amphoe) Phu Ruea on 15 October 1968 and made it a subordinate of Dan Sai. It was upgraded to a full district on 1 April 1974.