Mianwali District was an agricultural region having forests during the Indus Valley Civilization. Then, later on, Vedic Civilization took place. In 997 CE, Sultan Mahmud Ghaznavi took over the Ghaznavid dynasty empire established by his father, Sultan Sabuktigin. In 1005, he conquered the Shahis in Kabul, followed by the conquests of Punjab region. The Delhi Sultanate and later Mughal Empire ruled the region. The population of the Punjab region became majority Muslim, following the conquests by various Muslim dynasties from Central Asia.
Before the British rule, the area formed an integral portion of the Greco-Bactrian Empire of Kabul and the Punjab. Preceding the annexation of the Punjab by the British immediately after the Anglo-Sikh wars, this area became part of the Sikh Empire. During British Rule, the Indian Empire was sub-divided into provinces, divisions and districts.
After the independence of Pakistan, divisions remained the third tier of Government until 2000. The British had made the town of Mianwali as Tehsil Headquarters of Bannu District and then part of Dera Ismail Khan Division of Punjab province lately. The population of Mianwali, according to the 1901 Census of India, was 3,591. In 1901, Mianwali got the status of a District sharing its borders with eight districts (Attock, Khushab, Chakwal, Bhakkar, Karak, Lakki Marwat, Kohat and Dera Ismail Khan).