The black-veined white, Aporia crataegi (Lepidoptera: Pieridae), is distributed from northwest Africa throughout most of Europe and temperate Asia to far eastern Russia and Japan and is presumed to be extinct in South Korea, with only a few dried specimens remaining. A common conservation practice for such near-extinct species is the launch of an introduction program, but prior genetic analysis of donor and donee populations may be essential for the success of such a program. In the present study, we investigated the genetic diversity and the relationships of A. crataegi populations from South Korea and nearby Asian countries, using 11 newly developed A. crataegi-specific microsatellite markers and mitochondrial DNA (mtDNA) sequences from two genes (a total of 1317 bp from COI and CytB). mtDNA-based analyses, using a total of 115 individuals collected from China, Russia, Mongolia, and Japan and museum specimens from South Korea consistently showed long-held, close genetic relationships between A. crataegi populations from Mongolia, China, and Russia and those from South Korea, with the highest diversity detected in the Mongolian population. Principal coordinate analyses and STRUCTURE analyses, based on microsatellite markers, also suggested that A. crataegi from South Korea had a similar gene pool to populations from China, Mongolia, and Russia, with a similar degree of genetic diversity among these populations. Taken together, the mtDNA and microsatellite data suggest that the northern populations, particularly those from Mongolia, can be considered the most suitable population as an immediate donor for the near-extinct South Korean population of A. crataegi.