The mitochondrial genome (mitogenome) of Leucoptera malifoliella (=L. scitella) (Lepidoptera: Lyonetiidae) was sequenced. The size was 15,646 bp with gene content and order the same as those of other lepidopterans. The nucleotide composition of L. malifoliella mitogenome is highly A+T biased (82.57%), ranked just below Coreana raphaelis (82.66%) (Lepidoptera: Lycaenidae). All protein-coding genes (PCGs) start with the typical ATN codon except for the cox1 gene, which uses CGA as the initiation codon. Nine PCGs have the common stop codon TAA, four PCGs have the common stop codon T as incomplete stop codons, and nad4l and nad6 have TAG as the stop codon. Cloverleaf secondary structures were inferred for 22 tRNA genes, but trnS1(AGN) was found to lack the DHU stem. The secondary structure of rrnL and rrnS is generally similar to other lepidopterans but with some minor differences. The A+T-rich region includes the motif ATAGA, but the poly (T) stretch is replaced by a stem-loop structure, which may have a similar function to the poly (T) stretch. Finally, there are three long repeat (154 bp) sequences followed by one short repeat (56 bp) with four (TA)(n) intervals, and a 10-bp poly-A is present upstream of trnM. Phylogenetic analysis shows that the position of Yponomeutoidea, as represented by L. malifoliella, is the same as traditional classifications. Yponomeutoidea is the sister to the other lepidopteran superfamilies covered in the present study.