Simple SummaryParrots (Order: Psittaciformes) are an ancient arboreal lineage with a long history as companion animals for humans. Since at least the 1960s, released parrots have become established in non-native ranges globally. The method of their introduction is almost certainly a direct result of the pet trade through either accidental or intentional releases. Within the continental United States there are currently seventy-three naturalized parrot species that have been observed as of May 2023. Of these, close to half have established breeding populations. The propensity for a parrot species to become established appears to be phylogenetically driven. Notably, parrots in the family Cacatuidae and NeotropicalPyrrhuaare less successful at establishing themselves in the United States once released. We posit that what makes parrots such successful naturalized species are their charismatic nature paired with considerable intelligence and behavioral flexibility.AbstractParrots (Order: Psittaciformes) represent one of the most striking and ecomorphologically diverse avian clades, spanning more than two orders of magnitude in body size with populations occupying six continents. The worldwide diaspora of parrots is largely due to the pet trade, driven by human desire for bright, colorful, and intelligent animals as companions. Some introduced species have aptly inserted themselves into the local ecosystem and established successful breeding colonies all around the globe. Notably, the United States is home to several thriving populations of introduced species including red-masked parakeets (Psittacara erythrogenys), monk parakeets (Myiopsitta monachus), nanday conures (Aratinga nenday), and red-crowned amazons (Amazona viridigenalis). Their incredible success globally begs the question as to how these birds adapt so readily to novel environments. In this commentary, we trace parrots through evolutionary history, contextualize existent naturalized parrot populations within the contiguous United States, and provide a phylogenetic regression analysis of body mass and brain size based on success in establishing breeding populations. The propensity for a parrot species to become established appears to be phylogenetically driven. Notably, parrots in the family Cacatuidae and NeotropicalPyrrhuaappear to be poor at establishing themselves in the United States once released. Although brain size among Psittaciformes did not show a significant impact on successful breeding in the continental United States, we propose that the success of parrots can be attributed to their charismatic nature, significant intelligence relative to other avian lineages, and behavioral flexibility.