Khan Bahadur Ahsanullah (born 26 December 1873, Nalta Sharif, Undivided Bengal (today, part of Satkhira District, Bangladesh; died 9 February 1965, Nalta Sharif) was an educator, litterateur, Islamic theologist and social reformer of Pre-partition India. He was instrumental in the formation of the University of Dhaka and is the namesake of Ahsanullah University of Science and Technology.
Ahsanullah completed his MA in Philosophy from Presidency College, Kolkata in 1895, and went on to serve as first Muslim Headmaster of Rajshahi Collegiate School. He became the first person amongst the Hindus and Muslims of undivided Bengal to join the Indian Education Service (IES). He served as a Senator of the University of Calcutta, and was especially active in the movement to establish the University of Dhaka.
In 1958, Ahsanullah founded the Dhaka Ahsania Mission (DAM), a non-profit organization with broad social goals. In 1995, DAM founded the Ahsanullah University of Science and Technology, naming it in honor of their founder.
He wrote 78 books on different contents.