Sadullapur (Bengali: সাদুল্লাপুর) is an upazila of Gaibandha District in the Division of Rangpur, Bangladesh.

Sadullapur is located at 25°23′00″N 89°28′00″E / 25.3833°N 89.4667°E / 25.3833; 89.4667. It has 75,235 homes and a total area of 230.12 km.

According to the 2011 Bangladesh census, Sadullapur Upazila had 75,235 households and a population of 287,426. 67,631 (23.53%) were under 10 years of age. Sadullapur had a literacy rate (age 7 and over) of 44.07%, compared to the national average of 51.8%, and a sex ratio of 1047 females per 1000 males. 12,291 (4.28%) lived in urban areas.

As of the 1991 Bangladesh census, Sadullapur has a population of 243,012. Males constitute 50.4% of the population, and females 49.6%. The upazila's adult population, over 18 years, is 117,347. Sadullapur has an average literacy rate of 25.1% (7+ years), below the national average of 32.4%. The literacy rate of this upazila is 89.3.

Sadullapur Upazila is divided into 11 union parishads: Bongram, Damodorpur, Dhaperhat, Faridpur, Idilpur, Jamalpur, Kamarpara, Khodkomor, Noldanga, Rasulpur, and Vatgram. The union parishads are subdivided into 166 mauzas and 169 villages.

• Maqbular Rahman Sarkar (1928–1985), academic and tenth vice-chancellor of Rajshahi University

• Dhaperhat Union
• Districts of Bangladesh
• Divisions of Bangladesh
• Upazilas of Bangladesh