Relatedness, or the genetic similarity between individuals, can be used to understand dispersal dynamics, mating systems, kin selection, and inform conservation management. Most studies investigating kinship have been restricted to terrestrial organisms, whilst work on marine fauna has focussed primarily on cetaceans. The sawfishes (family Pristidae) are one of the most imperilled group of sharks and rays globally. Whilst the Largetooth Sawfish (Pristis pristis) is relatively well-studied, fine-scale genetic patterns, including relatedness, remain unexplored. Here we present a preliminary investigation of relatedness between 28 juvenile P. pristis from the Daly River of the Northern Territory, using genome-wide single nucleotide polymorphism data. Of 351 independent pairwise comparisons, 3.7% were first or second order relationships, comprising six full-sibling pairs, three half-sibling pairs, and one putative half-first-cousin pair. The average relatedness of individuals (± SD) was 0.027 ± 0.035. Relatedness was weakly correlated with the pairwise combination of location of capture between individuals (ρ = 0.053; F = 8.04; df = 5; pseudo R2 = 0.11; p < 0.0001). The presence of kin highlights the importance of the Daly River and its floodplain for juvenile P. pristis. Improved temporal coverage will help understand kinship dynamics of P. pristis in the Daly River.