The Olive-green Tyrannulet (Phylloscartes virescens) is a species of bird in the Tyrannidae family, the tyrant flycatchers. It is found in the Guianas of Suriname, French Guiana, and eastern Guyana, with the Essequibo River; also northeast Brazil, in the northeast Amazon Basin of Pará state, and Amapá. Its natural habitat is subtropical or tropical moist lowland forests.