Rajanpur was founded by Sheikh Rajan Shah, the makhdum of Sitpur, in about 1732. He had captured his estates from the previously ruling Nahar tribesmen. The settlement remained a largely unimportant village until flooding in 1862 severely damaged the nearby district headquarters at Mithankot leading to the transfer of government offices to Rajanpur. A small dispensary clinic was established in Rajanpur that same year. Rajanpur was then constituted as a municipality in 1873.