The Ponto-Caspian region is the main donor of invasive amphipods to freshwater ecosystems, with at least 13 species successfully established in European inland waters. Dikerogammarus spp. and Pontogammarus robustoides are among the most successful, due to their strong invasive impact on local biota. However, genomic knowledge on these invaders is scarce, while phylogeography and population genetics have been based on short fragments of mitochondrial markers or nuclear mi-crosatellites. In this study, we provide: (i) reconstruction of four mitogenomes for four invasive gammarids; (ii) comparison between the structure of the newly obtained mitogenomes and to those from literature; (iii) SNP calling rates for individual D. villosus and D. haemobaphes from different invasion sites across Europe; and (iv) the first time-calibrated full mitogenome reconstruction of several Ponto-Caspian taxa. We have sequenced, assembled and annotated four mitogenomes, each from D. villosus, D. hae-mobaphes, D. bispinosus and Pontogammarus robustoides. We found that, in comparison to other gammarids, the mitogenomes of Ponto-Caspian species show a translocation between the tRNA-E and tRNA-R positions. Phylogenetic reconstruction using the mitogenomes identified that Ponto-Caspian gammarids form a well-supported group that originated in the Miocene. Our study supports paraphyly in the family Gammaridae. These mitogenomes serve as vital genetic resources for the development of new markers for PCR-based identification methods and demographic studies.