We describe a new species of megophryid frog in the genus Leptolalax from central Vietnam. Leptolalax applebyi is distinguished from its congeners by a combination of body size (19.6–20.8 mm for five adult males; 21.7 mm for single adult female), uniformly smooth, dark brown dorsum lacking tubercles, dark brownish pink ventral surface with white speckling, an absence of webbing and dermal fringes on fingers, slight basal webbing and no dermal fringes on toes, and short tibia (TIB:SVL 0.466–0.480). The advertisement call of L. applebyi consists of 4–5 notes with a dominant frequency of 3962.1–4306.6 Hz, repeated at a rate of approximately 9 notes per second. All specimens were found at the headwaters of rocky streams in evergreen forest above 1300 m elevation. We suggest the species should be considered Data Deficient following IUCN’s Red List categories.