Abstract: To further elucidate mitochondrial genome structural variation, gene rearrangements, and phylogenetic relationships among Goneplacoidea and related taxa. In this study, the mitochondrial genomes of Entricoplax vestita and Eucrate solaris were independently resequenced, assembled, and annotated, and comparative mitogenomic and phylogenetic analyses were conducted using publicly available mitochondrial genomes of Goneplacoidea and related taxa. Results showed that the mitochondrial genomes of E. vestita and E. solaris were 15878 bp and 15671 bp in length, respectively. Both genomes were typical closed circular double-stranded DNA molecules and contained 13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs, with a pronounced A+T bias and relatively consistent codon usage patterns. Comparative analysis of gene order identified three arrangement patterns. E. vestita retained the ancestral gene arrangement of Brachyura, whereas E. solaris shared a local gene rearrangement pattern with Eucrate crenata. Phylogenetic trees inferred from 13 PCGs using Bayesian inference and maximum likelihood methods recovered two major lineages within Goneplacoidea. Under the current limited taxon sampling, the three sampled Eucrate species did not cluster into a single clade. E. solaris and E. crenata formed a closely related lineage and shared a local mitochondrial gene rearrangement pattern, whereas E. alcocki occurred in a separate lineage and retained the ancestral gene arrangement. These results suggest potentially complex lineage differentiation within Eucrate, this study provides additional data for comparative mitogenomic and phylogenetic studies of Goneplacoidea.