Signature whistles (SWs) are a key component of delphinid vocal repertoires, encoding self-identifying information and facilitating cohesion among related or allied individuals through stereotyped whistles. SWs allow researchers to identify individuals, assess social dynamics, and estimate population size without visual observation. This study represents the first attempt to match distinct SWs to individual Burrunan dolphins (Tursiops australis) in the Gippsland Lakes, Victoria, Australia. Simultaneous photographic identification and hand-held hydrophone recordings captured 57 dolphins producing 236 whistles, from which 22 unique SW contours were extracted following modified SIGnature IDentification (SIGID) criteria. Conditional probability and cluster analyses associated SWs with dolphin pairs or clusters rather than isolated individuals, reflecting the species’ fission–fusion social dynamics. Social structure, philopatry, and acoustic environment likely influence SW production and complexity. While direct individual matching is limited, the findings demonstrate the potential of passive acoustic monitoring for population-level conservation management of this small, threatened population.