Map - Dera Ismail Khan District (Dera Ismāīl Khān District)

Dera Ismail Khan District (ډېره اسماعیل خان ولسوالي, ڈیرہ عِسمائیل خان,, ; often abbreviated as D.I. Khan) is a district in Dera Ismail Khan Division of Khyber Pakhtunkhwa province in Pakistan. The capital of the district is the town of Dera Ismail Khan. The district has an area of 9334 km2 and a population of 1,627,132 as of the 2017 Census.

The district of Dera Ismail Khan is bounded on the east by the Bhakkar and Dera Ghazi Khan districts of Punjab. Eastern portions of the district along the Indus River are characterized by fertile alluvial plains, while lands farther from the river consist of clay soil cut by ravines from rainfall. The district is bounded on the southwest by a thin strip of the South Waziristan district, formerly of the Federally Administered Tribal Areas, which separates D.I Khan from the Takht-e-Sulaiman Mountain in the neighboring Baluchistan province. In the northwest is the Tank District.

D.I Khan is separated from the Marwat plains of the Lakki Marwat district by a spur of clay and sandstone hills that stretch east from the Sulaiman Mountains to the Indus River known as the Sheikh Badin Hills. The highest peak in the range is the limestone Sheik Badin Mountain, which is protected by the Sheikh Badin National Park. Near the Indus River is a spur of limestone hills known as the Kafir Kot hills, where the ancient Hindu complex of Kafir Kot is located. DI Khan is also considered the center of Pakistan because of its location between Bhakkar of South Punjab, Mianwali of North Punjab, Zhob of Balochistan and South Waziristan of Pakistan tribal belt.