Leeches were sampled from 2 turtle species, Chelodina burrungandjii and Emydura australis, from 9 rivers spanning the Kimberley Plateau of Western Australia, Australia. Placobdelloides octostriata was collected from both turtle taxa across the Kimberley Plateau, and Bogobdella diversa was collected from a single specimen of E. australis in the Fitzroy River, the westernmost catchment of the sample area. Relative prevalence of P. octostriata was influenced by host behavior, with a 10-fold difference in prevalence on the sit-wait predator C. burrungandjii (37.4–42.2%) in comparison with the more actively swimming E. australis (1.3–3.7%). The prevalence of parasitism was not substantially different between sites for each species. These are new host and locality records for Euhirudinea in Australia.