Assessing the genetic diversity of captive populations of endangered species is key to the successful management of conservation-breeding programs. In this study, we sequenced a 393-bp fragment of the mitochondrial DNA (mtDNA) control region of 23 captive individuals of the Endangered François’ langur (Trachypithecus francoisi) to assess the mtDNA diversity of the European captive population and to identify the possible geographical origins of the population founders. Combined with 42 sequences previously published from 29 wild François’ langurs, we identified a total of 40 haplotypes in T. francoisi, including 12 haplotypes in the 23 samples from the European captive population. Only one of the haplotypes from captive animals has previously been reported from wild populations; the remaining 11 haplotypes are newly reported here. Our results suggest that the captive T. francoisi population currently holds a relatively good genetic diversity compared with many other captive populations, that this diversity originates from a fairly broad range across the species’ distribution in the wild, and that the captive population could play a significant role in increasing genetic diversity of isolated wild populations. However, the European captive population is currently quite small, and genetic diversity could be lost rapidly, which has been demonstrated in other captive populations. We recommend further investigation of the genetic diversity of captive and wild T. francoisi populations, as well as the effective conservation of this diversity.