Many sharks and rays live in coastal environments to access shelter and prey, which increases their susceptibility to environmental (temperature, waves, freshwater input) and anthropogenic (wastewater, pollution) changes compared to pelagic ecosystems. The ecological value of nearshore habitats also leads to co-occurring communities of sharks and rays competing for resources. We used acoustic telemetry to investigate the movement and spatial overlap between Port Jackson sharks (n = 65) and southern eagle rays (n = 21) in Gulf St Vincent, South Australia. Port Jackson sharks exhibited seasonal site fidelity, moving to more estuarine environments during winter and returning to reef sites in summer. Southern eagle rays demonstrated high, year-round site fidelity to the area they were tagged, with no seasonal changes in residency. These different movements limited the extent of spatial overlap between the species, reducing competition for resources at key sites. We identified the importance of coastal environments for Port Jackson sharks and southern eagle rays, and found no movement beyond the Gulf St Vincent for these species, which could increase their susceptibility to local pressures. This information provides a powerful baseline for future management of these species and as potential ecological indicators of healthy coastal environments.