Dhamrai and Manikganj Sadar upazilas on the north, Nawabganj (Dhaka) upazila on the south, Savar and Keraniganj upazilas on the east, Manikganj Sadar upazila on the west.

Singair thana was established in 1919 and was turned into an upazila in 1983. It consists of 11 union parishads, 140 mouzas and 236 villages.

Singair Upazila is located in Manikganj District. Upazilla(s)/Thana(s) in Manikganj are Daulatpur Upazila, Ghior Upazila, Harirampur Upazila, Manikganj Sadar Upazila, Saturia Upazila, Shivalaya Upazila, Singair Upazila.

Fort at Fordnagar, Neel-kuthi at Baira, Imampara Jami Mosque (Paril), tomb of Ibrahim Shah (Paril, Naohadda), Mosque near Paril Bazar (1904), residence of the Datta-Guptas, Ananda Kuthi and Mandir (Baldhara), Sen-bari and Durga-mandapa (Baldhara), Kali-sundari Charitable Dispensary (1895).