Alamdanga () is an upazila of Chuadanga District in Khulna, Bangladesh. It covers an area of .
Alamdanga is located at . It has 86,299 households and an area 364.66 km<sup>2</sup>.
According to the 2022 Bangladeshi census, Alamdanga Upazila had 99,903 households and a population of 368,189. 7.71% of the population were under 5 years of age. Alamdanga had a literacy rate (age 7 and over) of 68.70%: 69.66% for males and 67.79% for females, and a sex ratio of 95.23 males for every 100 females. 60,077 (16.32%) lived in urban areas.
Alamdanga Thana was turned into an upazila in 1982 under Hussain Muhammad Ershad's decentralization programme.
Alamdanga Upazila is divided into Alamdanga Municipality and 15 union parishads: Ailhash, Belgachi, Baradi, Bhangbaria, Chitla, Dauki, Gagni, Hardi, Jamjami, Jehala, Kalidashpur, Khadimpur, Khashkorara, Kumari, and Nagdah. The union parishads are subdivided into 126 mauzas and 211 villages.
Alamdanga Municipality is subdivided into 9 wards and 18 mahallas.