Saiful Islam Khan (known as Hayat Saif; 16 December 1942 – 13 May 2019) was a twentieth century modern Bengali poet and literary critic from Bangladesh. A career bureaucrat, he retired in 2000 and since then was engaged in the corporate private sector and divided his time in World Scouting and literary and artistic pursuits. He has been translated in English and Spanish and, in Bangladesh, is generally acclaimed as an intellectual interpreter of contemporary life and culture.