Amy B. H. Greenwell Ethnobotanical Garden, Protected botanical garden in Captain Cook, Hawaii

The Amy B. H. Greenwell Ethnobotanical Garden is a 12-acre (4.9 ha) botanical garden on the western slope of Mauna Loa, uphill of the Hawaii Belt Road in Captain Cook. It holds over 200 species of endemic, indigenous, and Polynesian-introduced plants that grew in Kona before Captain James Cook's arrival, arranged across four ecological zones: coastal, dry forest, agricultural, and upland forest.

Amy Beatrice Holdsworth Greenwell, born in 1920, planted native and Polynesian-introduced species on her family land and left the garden to the Bishop Museum on her death in 1974. The museum closed it to the public on 31 January 2016 and sought a buyer; in November 2019 the Friends of the Garden bought the land and reopened it on 29 February 2020.

The garden preserves traditional Hawaiian agricultural methods through stone structures and techniques that show how people in the Kona region once grew their plants. Visitors can see these old practices reflected in the landscape today and understand how closely Hawaiians were connected to their land.

The garden lies uphill (mauka) of Hawaii Belt Road, also called Mamalahoa Highway or Route 11, on the western slope of Mauna Loa. It is open Thursday through Sunday from 9 am to 2 pm, with free admission and donations accepted. The grounds cover four zones, from coastal to upland forest, so allow time to walk the whole site.

The grounds span four different ecological zones ranging from coastal areas to mountain forests, showing how varied Hawaiian nature can be. A special insect house shelters the Kamehameha butterfly, an important part of the local ecosystem.