Sunamganj Sadar and Jamalganj upazilas on the north, Sullah and Nabiganj upazilas on the south, Jagannathpur on the east, Khaliajuri, Sullah and Jamalganj upazilas on the west.

Derai upazila was established in 1982. It consists of 9 union parishads, 165 mouzas, 233 villages.

Derai Upazila is located in Sunamganj District. Upazilla(s)/Thana(s) in Sunamganj are Bishwamvarpur Upazila, Chhatak Upazila, Derai Upazila, Dharmapasha Upazila, Dowarabazar Upazila, Jagannathpur Upazila, Jamalganj Upazila, Sullah Upazila, Sunamganj Sadar Upazila, Tahirpur Upazila.