The first occurrence of an invasive pest species, the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), in Bulgaria is reported. Different trapping methods (black light trap, traps baited with semiochemical lures, and food attractants) were used to study Noctuidae assemblages in Bulgaria in 2023. Two males of S. frugiperda were caught with sex pheromone traps in maize fields in Knezha, northern Bulgaria, in early November 2023. Additionally, three moths were attracted by black light traps (early November 2023) and one moth by a food lure applied on a tree trunk at the end of October 2023 in the municipalities of Parvomay and Chirpan, southern Bulgaria, respectively. The identification of S. frugiperda was confirmed using morphological and molecular methods.