The Monteverde Cloud Forest Reserve (Spanish: Reserva Biológica Bosque Nuboso Monteverde) is a Costa Rican reserve located along the Cordillera de Tilarán within the Puntarenas and Alajuela provinces. Named after the nearby town of Monteverde and founded in 1972, the Reserve consists of over 10,500 hectares (26,000 acres) of cloud forest. It draws roughly 70,000 visitors a year. The reserve consists of six life zones, 90% of which are virgin forest. A high biodiversity area, consisting of over 2,500 plant species (including the most orchid species in a single place), 100 species of mammals, 400 bird species, 120 reptilian and amphibian species, and thousands of insects, has drawn both scientists and tourists alike.

In 1951, several dozen Quakers (from 11 families) from Alabama seeking to live as farmers moved to and purchased land in Costa Rica. This was primarily to avoid the Korean War draft, an obligation which contradicted Quaker pacifist ideology. They chose Costa Rica because it had abolished its army just three years earlier. It was the Quakers who named the place Monteverde ("Green Mountain"), for round-the-year green plants.

Biologists began to take note of Monteverde in the 1960s. Despite the lack of infrastructure and shelter with which to conduct scientific research, these original biologists not only have been continuously documenting, but continue to live in, Monteverde.

In 1968, Joseph Tosi, who worked for the Tropical Science Center, a foundation for tropical conservation, accompanied Leslie Holdridge on a journey to Monteverde. The visit was part of a study of the northern region of Costa Rica, requested by the government's National Planning Office. There, they met Hubert Mendenhall, leader of the Quaker community at the time, who took them to see the primary forests that surrounded the community.

At the end of their visit, Holdridge and Tosi recommended to the Quaker community that the native forests be preserved as much as possible in order to protect their water sources and, given the strong winds that swept though the area, to use the forests as windbreakers to protect their fields and homes.

In 1972, a young graduate student, George Powell, visited the Tropical Science Center (TSC) in San José. He lived in Monteverde while doing doctoral research on the birds of the area, and he found that the fauna and habitats were ideal for research purposes.

Amazed by the extraordinary biological richness of the cloud forests, including the habitat of the endemic golden toad, and alarmed by the depredation caused by hunters and land squatters, Powell received a promise from the Guacimal Land Company that they would donate 328 hectares (810 acres) of land, if he could form or find a civic association that would sponsor him in taking over the property. George used his personal funds to buy out several of the squatters, hoping to establish a small biological preserve in the region.

At the time, there were few national parks in Costa Rica, and the TSC had a program to create private preserves for research and biological education, where each preserve would represent a different ecological area of the country. Immediately, the TSC became interested in Powell's offer and started the process that led to the acquisition of the 328 hectares (810 acres) in April 1973. The cost of the farm was a symbolic 1 colón (less than USD $1).