Rohan David Pethiyagoda is a Sri Lankan biodiversity scientist, amphibian and freshwater-fish taxonomist, author, conservationist and public-policy advocate.

He served as Advisor on Environment and Natural resources to the Government of Sri Lanka from 2002 to 2004 and was in 2005 elected Deputy Chair of the IUCN Species Survival Commission.

[3] In 2008 Pethiyagoda was elected to the board of trustees of the International Trust for Zoological Nomenclature, having previously served a four-year term as Deputy Chair of the Assurance Group of the British American Tobacco Biodiversity Partnership.

[10][11][12][13] This program aimed, for the first time in Sri Lanka, to put scientific local-language biodiversity texts in the hands of young people.

[42] In 2020, a team of scientists led by S. D. Biju named a new genus of South and Southeast Asian tree frogs Rohanixalus in Pethiyagoda's honour.