Lyriothemis mortoni (Ris, 1919) is found only in Southeastern Asian, from Myanmar, Thailand, Viet Nam.

Known from the holotype from Myanmar (Ris 1919, Fraser 1936), the only relatively recent records of this species are of 16 individuals collected in Chantaburi in Thailand in 1981 over two days plus another collected in Chumphon (Asahina 1988), and the  photographic record from Trang in Thailand, dating from 2009, on the Asia Dragonfly website. These suggests that Lyriothemis mortoni can be common where it occurs. But there have no other data on population. In 2007, the Viet Nam based non-profit organization Wildlife at Risk (WAR) had first discovered this species in Viet Nam in southern Phu Quoc Island.

Nothing has been recorded about the habitat of this species but other species of Lyriothemis are confined to forest areas, their breeding habitat is typically small pools and marshy areas in forest, or in phytotelmata (water containing compartments in plants, e.g. tree holes).

Although the records from Thailand suggest that the species may be common where it occurs, there still have inadequate data on which to base estimates of population, and on distribution, and can only guess at its habitat requirements. In these circumstances Lyriothemis mortoni is accessed by IUCN Red List as Data Deficient.