The Department of Biological Sciences evolved from the merger of two of the oldest departments in the Faculty of Science: the Department of Botany and the Department of Zoology. Botany, founded in 1949, turned 50 in 1999; and Zoology, founded in 1950.
Professor Lam Toong Jin, Head of Zoology (1981 - 1996), then Director of School of Biological Sciences (1996-1998) and finally Head of Department of Biological Sciences (1998-1999) handed the headship baton to Professor Hew Choy Leong in October 1999 and Professor Paul Matsudaira took over the headship from 2009 to 2017, after which the Department was headed by Professor Yu Hao from July 2017.
There was a School of Biological Sciences, briefly, for two years when the former Botany and Zoology first merged. The University subsequently changed the name to Department of Biological Sciences in 1998.