The South and South‐East Asian freshwater fish genus Systomus (Cyprinidae) comprises 17 valid species. Six nominal species, including three endemics, have been reported from Sri Lanka, a continental island separated from India by a shallow‐shelf sea. The species diversity of Systomus on the island has until now not been assessed; neither has an evaluation been made of their phylogenetic history. Here, based on an analysis of t...