Originally, Tambon Pho Thean was under Tambon Bang Pla Kot and separated into Pho Sub-District 20 years ago. The sub-district is called Pho Tan after the name of Wat Pho Thaen. At Wat Pho Thaen, there is a Bodhi tree and later the Bodhi tree collapsed and died, and a new Bodhi tree grew up replacing the old Bodhi tree, hence it is called Pho Thaen. Currently, Tambon Pho Thaen is a sub-district in the administrative district of Ongkharak District which consists of 9 villages, namely Ban Khmer Tai, Ban Khlong 14, Ban Mahawong, Ban Pho Thaen, Ban Lat Sa-ed, Ban Pak Ban, Ban Khmer Nua, Ban Ong Phat, and Ban Khlong Ton Tan.