Saidpur () is an upazila of Nilphamari District in Rangpur Division, Bangladesh. Saidpur thana, later turned into an upazila, was established in 1915. Before 1870, Saidpur was a Bazar under Daroani thana of Rangpur district. It was under Nilphamari Sadar thana of Nilphamari Mohokuma between 1870 and 1915.
Saidpur is located at . The upazila is bounded by Nilphamari Sadar and Kishoreganj upazilas on the north-east, Badarganj and Parbatipur upazilas on the south, Taraganj upazila on the east, Chirirbandar and Khansama upazilas on the west.Saidpur Upazila Surrounding With All 3 Districts (Nilphamari, Dinajpur & Rangpur). Total area of Saidpur is 121.66 km<sup>2</sup>.
According to the 2022 Bangladeshi census, Saidpur Upazila had 73,574 households and a population of 312,993. 9.60% of the population were under 5 years of age. Saidpur had a literacy rate (age 7 and over) of 74.07%: 76.30% for males and 71.82% for females, and a sex ratio of 101.69 males for every 100 females. 161,519 (51.60%) lived in urban areas.
According to the 2011 census of Bangladesh, Saidpur Upazila had 58,137 households and a population of 264,461. 58,868 (22.26%) were under 10 years of age. Saidpur had a literacy rate (age 7 and over) of 54.56%, compared to the national average of 51.8%, and a gender ratio of 977 females per 1000 males. 130,041 (49.17%) lived in urban areas.
As of the 1991 Bangladesh census, Saidpur has a population of 199422. Males constitute 52.19% of the population, and females 47.81%. This Upazila's eighteen up population is 98745. Saidpur has an average literacy rate of 38.7% (7+ years), and the national average of 32.4% literate.
Saidpur Upazila is divided into 1 municipality (Saidpur Municipality) and six union parishads: Bangalipur, Botlagari, Kamarpukur, Kasirambelpukur, Khatamadhupur, and Saidpur Cantonment. The union parishads are subdivided into 42 mauzas and 39 villages.
Saidpur Municipality is subdivided into 15 wards and 43 mahallas.