Felix Prashantha Amerasinghe (14 July 1948 – 7 June 2005) was a Sri Lankan entomologist who studied arthropods of medical importance including ticks and mosquitoes and their role in the spread of diseases such as malaria, dengue, Japanese encephalitis, and lyme.
He studied at St Anthony's College, Katugastota and then at the University of Peradeniya from where he graduated in zoology in 1971.
He returned to Sri Lanka and continued working as a lecturer, professor (1996) and head of the department of zoology (1998).
His major contribution was on the study of Japanese encephalitis in Sri Lanka.
His Priyanie was also a researcher and they worked together in the University of Maryland between 1990 and 1992, studying and monitor ticks involved in the transmission of lyme disease.