Entomopathogenic fungi of the genus Metarhizium are widely used as biological control agents; however, their performance in arid and semi-arid regions is strongly constrained by high temperatures. This study aimed to isolate and identify native thermotolerant Metarhizium strains from soils collected in four Moroccan southeastern oases (Erfoud, Rissani, Goulmima, and Aoufous) in the Drâa-Tafilalet region. A total of 82 isolates of Metarhizium were obtained, and 40 isolates were selected randomly and screened for thermotolerance by assessing conidial germination after heat exposure at 45 °C for 2 hours. Inter— and intra—population variability was observed, with germination rates ranging from 75% to 95.67%. Among all tested isolates, strains R2 and R4 from Rissani oasis exhibited the highest thermotolerance and were therefore selected for molecular identification. The identification of Metarhizium strains R2 and R4 was conducted phylogenetically based on a concatenated dataset of ribosomal internal transcribed spacer region (ITS) and the translation elongation factor 1-alpha (TEF-1α) sequences. Both strains were assigned to Metarhizium robertsii and clustered within the same terminal branch as three reference strains of M. robertsii (ARSEF 4739, ARSEF 727 and ARSEF 8020) supported by a high bootstrap value (92 %). Pathogenicity assays against Tenebrio molitor larvae confirmed high virulence (86.67–100 % mortality), further supporting their potential as effective biocontrol agents. The presence of highly thermotolerant M. robertsii in Moroccan oases suggests strong local adaptation to extreme thermal conditions and highlights promising candidates for developing climate-resilient biopesticides suitable for hot and arid agroecosystems. These results contribute to a better understanding of the ecological distribution and stress tolerance of Metarhizium spp. oasis habitat and support their integration into sustainable pest management strategies.