[5] According to the 2011 Census of Bangladesh, Sirajganj Sadar Upazila had 125,485 households and a population of 555,155.

Sirajganj Sadar had a literacy rate (age 7 and over) of 47.96%, compared to the national average of 51.8%, and a sex ratio of 989 females per 1000 males.

[7][8] As of the 1991 Bangladesh census, Sirajganj Sadar has a population of 389,160.

[9] Sirajganj Sadar Thana was formed under Mymensingh district in 1772 and it was turned into an upazila in 1984.

[10] Sirajganj Sadar Upazila is divided into Sirajganj Municipality and ten union parishads: Bagbati, Bohuli, Kaliahoripur, Khokshabari, Kawakhola, Mechhra, Ratankandi, Shialkol, Chhongachha, and Soydabad.