Michael Patrick Hassell CBE FRS (born 2 August 1942) is a British biologist, noted for his work in population ecology, especially in insects.
He later worked as a research fellow at the University of California, Berkeley and at Oxford.
Hassell became dean of the Imperial College campus at Silwood Park in 1988 and Head of the Department of Biology and Biochemistry in 1993.
Hassell is also a fellow of the Academia Europaea, a trustee of the Natural History Museum, a member of the Natural Environment Research Council, and a member of the council of the Zoological Society of London.
Hassell became a Commander of the Order of the British Empire in 2002 when he was named on the Queen's Birthday Honours list.