Jamalpur Sadar () is an upazila of Jamalpur District in Mymensingh, Bangladesh.
Jamalpur Sadar is located at . It has a total area of 508.80 km<sup>2</sup>. It is bounded by Sherpur district to the north, Mymensingh district to the east, Tangail district of Dhaka division to the south, and Melandaha, Madarganj and Sarishabari upazilas on the west.
According to the 2022 Bangladeshi census, Jamalpur Sadar Upazila had 176,033 households and a population of 668,243. 8.97% of the population were under 5 years of age. Jamalpur Sadar had a literacy rate (age 7 and over) of 67.41%: 69.98% for males and 65.06% for females, and a sex ratio of 93.16 males for 100 females. 210,174 (31.45%) lived in urban areas.
Jamalpur Sadar Upazila is divided into Jamalpur Municipality and 15 union parishads: Banshchara, Digpaith, Ghoradhap, Itail, Kendua, Lakshmir Char, Meshta, Narundi, Ranagachha, Rashidpur, Sahabajpur, Sharifpur, Sreepur, Titpalla, and Tulsir Char. The union parishads are subdivided into 250 mauzas and 365 villages.
Upazila Nirbahi Officer (UNO): Mohammad Abdul Salam