This study investigated the diet of the red fox (Vulpes vulpes) in a mountain ecosystem (Djurdjura National Park), with a particular focus on potential seasonal variation. A total of 360 fecal samples collected over a full year yielded 1051 food items, which were classified into ten trophic categories. Analyses indicated a highly heterogeneous diet, reflecting the species’ generalist and opportunistic foraging strategy. Mammals constituted the primary food source, followed by plants and arthropods. The wood mouse (Apodemus sylvaticus) emerged as the predominant prey throughout the year, likely due to its high availability and/or a strong predatory preference. Seasonal dietary shifts were evident with plant consumption increasing during the dry season, while mammalian prey became more prominent during the rainy season.