This database contains acoustic telemetry data for euryhaline elasmobranchs in northern Australian rivers. Data was collected under the National Environmental Research Program (NERP) Marine Biodiversity Hub Project 2.4 'Supporting Management of Listed and Rare Species', and the National Environmental Science Program (NESP) Marine Biodiversity Hub Project A1 'Northern Australian Hotspots for the Recovery of Threatened Euryhaline Elasmobranchs'. An acoustic receiver array was deployed in the Adelaide River, and another in the Alligator Rivers (primarily the South Alligator River) to monitor the movements, habitat use and natural mortality of threatened river sharks (Glyphis species) and sawfishes (Pristis species). Receiver deployment data is available through the IMOS Animal Tracking Facility database (visit https://animaltracking.aodn.org.au/receivers/deployment and search for project 'NESP Northern Australian hotspots for the recovery of threatened euryhaline species'). Raw and processed (cleaned) detection data is attached to this record.