We evaluated the utility of DNA barcodes for identifying Thaumatotibia leucotreta (Meyrick) infesting sweet oranges in Nigeria. Approximately 658 bp of the mitochondrial gene cytochrome oxidase subunit I (COI) was amplified, sequenced, and analyzed for 32 adult samples, eight from each of the four geopolitical zones of Nigeria. All of the samples had identical sequences except for two, both of which showed a transition from “G” to “A” at position 433 bp. DNA barcodes of specimens from Nigeria showed 100% similarity with sequences of T. leucotreta in the Barcode of Life Database (BOLD) from Kenya and South Africa; all the Nigerian samples cluster with T. leucotreta from BOLD with a bootstrap support of 90. DNA barcoding is consistent with identifications of the samples based on morphology.