Background: Babesiosis, a tick-borne disease caused by protozoans of the genus Babesia, is widespread in subtropical and tropical countries. Mitochondrion is an essential organelle that is responsible for energy transduction and metabolism, calcium homeostasis and cell signaling. Mitochondrial genomes could provide a new insight to understand and explore the population genetics, biological features of the pathogens, and evolutionary relationships. However, there is limied information on the mitochondrial genomes of ovine Babesia spp. in China.Methods: Herein, we sequenced, assembled and annotated the mitochondrial genomes of six ovine Babesia isolates, and analyzed genome size, gene content, genome structure and cytochrome b (cob) amino acid sequences, and performed comparative mitochondrial genomics and phylogenomic analyses among apicomplexan parasites.Results: The mitochondrial genomes range from 5767 to 5946 bp in length with a linear form and contain three protein-encoding genes, cytochrome c oxidase I (cox1), cytochrome c oxidase III (cox3) and cob, six large subunit rRNA gene (LSU), and two terminal inverted repeats (TIR) on both ends. The cob sequence analysis indicated that the binding site of anti-Babesia drugs targeted on the cytochrome bc1 complex. Babesia microti and Babesia rodhaini have a dual flip-flop inversion of 184-1082 bp, whereas other Babesia spp. and Theileria spp. have one pair of TIR, 25-1563 bp. Phylogenetic analysis indicated that six ovine Babesia isolates were divided into two clades, Babesia sp. and Babesia motasi. B. motasi isolates were further separated into two subclades (B. motasi Lintan/Tianzhu and B. motasi Ningxian/Hebei).Conclusions: The data provided new insights into the population genetics, taxonomic relationships, molecular epidemiological studies and drug targets of apicomplexan parasites.