The complete mitochondrial genome sequences of the two butterfly speciesEuploea mulciber(Lepidoptera: Nymphalidae: Danainae) andLibythea celtis(Lepidoptera: Nymphalidae: Libytheinae) were determined in this study, comprising 15,166 bp and 15,164 bp, respectively. The orientation and the gene order of the two mitogenomes are identical to those of most of the other lepidopteran species. All protein-coding genes ofEuploea mulciberandLibythea celtismitogenomes start with a typical ATN codon with the exception of COI gene which uses CGA as its initial codon. All tRNA genes possess the typical cloverleaf secondary structure except for tRNASer(AGN), which has a simple loop with the absence of the DHU stem. There are short microsatellite-like repeat regions, but no conspicuous macrorepeats scattered throughout the A + T-rich regions. Phylogenetic analysis among the available butterfly species suggests thatLibythea celtis(Libytheinae) is closely related toCalinaga davidis(Calinaginae), indicating that the subfamily Libytheinae may not represent a basal lineage of the Nymphalidae as previously suggested, and thatEuploea mulciberstands at the base of the nymphalid tree as a sister to all other nymphalids.