Bull shark swims peacefully in Beqa Fiji, 2007
Carcharhinus leucas, a freshwater Bull shark, swims in Fiji 2007

Freshwater sharks are sharks able to live in freshwater lakes and rivers, including:

Some prehistoric sharks (in a broad sense), including hybodonts and xenacanths, are also thought to have inhabited freshwater environments.

A small number of freshwater fish cyprinids and catfish (which are bony fish and thus quite unrelated to sharks) are also commonly called "freshwater sharks", "sharkminnows" or simply "sharks", particularly in the aquarium fish trade: