The Olive Warbler is a taxon of uncertain affinities. Although it long had been associated with New World wood-warblers (Parulidae) - and sometimes even treated as a member of the genus Dendroica - evidence from anatomical and DNA studies has recently placed it into its own monotypic family, Peucedramidae. The sister taxon to Peucedramidae has not been identified, but there some studies of molecular phylogeny link it to the Prunellidae, a small Old World family.
Superficially, this species seems a typical warbler. The Olive Warbler is an oscine with orange-brown head and 9-primaries that is generally found in pine forests of high mountains from Nicaragua north barely into the southwestern United States. Also found in mixed oak-pine (Pinus-Quercus) woodlands, it uses pines almost exclusively for foraging and nesting. Although relatively common, this species has been studied little in the field. It is a bird of the high canopy that nests far out on high branches of pines.