Understanding trophic interactions of marine mesopredators is essential for evaluating ecosystem functioning and supporting ecosystem-based fisheries management. The small-spotted catshark, Scyliorhinus canicula, is one of the most abundant demersal elasmobranchs in the Mediterranean Sea. This study investigated the trophic ecology of S. canicula in the southern Tyrrhenian Sea through the analysis of the stomach contents of 244 individuals collected between 2020 and 2024. Diet composition, trophic niche breadth, trophic level, resource partitioning, and trophic overlap were assessed in relation to size class, maturity stage, bathymetric distribution, and sampling year. Multivariate analyses included nMDS, PERMANOVA, SIMPER, null-model approaches based on Pianka and Morisita–Horn overlap indices and Generalized Additive Models (GAMs) to investigate environmental and ontogenetic drivers of prey occurrence. The overall diet was dominated by teleost, crustaceans, and cephalopods, with Osteichthyes (20.53% PSIRI) and Penaeoidea (18.58% PSIRI) representing the most important preys. The species exhibited a high trophic position (TROPH = 4.17 ± 0.55), confirming its role as a mesopredator within Mediterranean Sea food webs. Levins’ index indicated a specialist trophic strategy at the population level (B_i = 0.38), although mature individuals displayed a broader trophic niche (B_i = 0.62). Diet composition was significantly influenced by bathymetry, body size and maturity stage, with depth representing the strongest explanatory factor. GAM analyses revealed marked prey-specific responses to environmental and biological drivers, with predictor importance analyses identifying depth as the most influential variable driving prey occurrence patterns. Trophic overlap among ecological groups remained consistently high between Size Classes and Maturity Stages, while was moderate between Depth Classes, suggesting the absence of a complete niche segregation. Overall, data from the present study improve the knowledge base on the resource partitioning dynamics influencing the populations of S. canicula, providing important information on the ecology of this essential mesopredator from the Central Mediterranean Sea.