Sierra del Rosario is a mountain range in the provinces of Pinar del Río and Artemisa, Cuba. It is located in the western part of the Guaniguanico Range, in the north-western part of the province of Pinar del Río and in the eastern part of Artemisa's one; between the municipalities of La Palma, Los Palacios, Consolación del Sur, Bahía Honda, Candelaria and San Cristóbal.
It was established as a Biosphere Reserve and an IUCN Managed Resource Protected Area on February 15, 1984, being the first one in Cuba to be classifid as such. It protects a total area of 266.86 km2 (103.04 sq mi), of tropical forests with evergreen and semi-deciduous environments.
Over 800 species of plants are hosted in the mesic forest that covers the mountains, with 35% being endemic. Fauna includes five species of bats, numerous birds (notably the Bee hummingbird), as well as the Yellow-Striped Pygmy Eleuth (Eleutherodactylus limbatus), one of the smallest frogs in the world, and various lizards such as the Anolis luteogulartis.