Banaj Kumar Majumder (Bengali: বনজ কুমার মজুমদার; born 1 January 1967) is a Bangladeshi retired police officer.

Banaj Kumar Majumder’s contributions to the PBI and to the broader field of law enforcement in Bangladesh reflect his profound dedication to duty, his strategic foresight, and his unwavering ethical standards, making him a respected figure in the fight against crime in Bangladesh.

[6][7] Majumder, then additional commissioner of Chattogram Metropolitan Police, provided financial assistance to the family of a constable killed in the line of duty in 2013.

His elder brother, Mihir Kanti Majumder, was a secretary of the government of Bangladesh who sought nomination from Awami League for the 12th parliamentary election.

He played a pivotal role in several high-profile investigations, which not only brought criminals to justice but also showcased his commitment to upholding the law.