Machadinho d'Oeste is a municipality located in the Brazilian state of Rondônia. Its population was 40,867 (2020) and its area is 8,509 km². The municipality contains part of the 346861 ha Jaru Biological Reserve, a fully protected conservation unit created in 1984. It also contains 13% of the Campos Amazônicos National Park, a 961318 ha protected area created in 2006 that protects an unusual enclave of cerrado vegetation in the Amazon rainforest. The municipality contains 78% of the Angelim Extractive Reserve and 79% of the Ipê Extractive Reserve. It also contains the Castanheira, Freijó, Garrote, Itaúba, Jatobá, Maracatiara, Massaranduba, Mogno, Piquiá, Roxinho and Sucupira extractive reserves.