Introduced species are major drivers of biodiversity loss worldwide. Several squamate taxa have become established outside of their native ranges after human-mediated transportation, becoming a conservation concern. We report on the occurrence of an exotic anole lizard in the Baixada Santista region in coastal Brazil. To clarify the species' identity and examine the geographic source of its introduction, we generated sequences of one mitochondrial DNA marker. The anole is genetically closest to species in the Anolis carolinensis group (Dactyloidae), which does not occur naturally in South America. Phylogenetic analyses found that samples from Brazil nest within A. porcatus, a Cuban species that has also been introduced into Florida and the Dominican Republic. Results indicate that Brazilian A. porcatus are nested among samples from La Habana, Matanzas, and Pinar del Río, which may suggest a western Cuban source of introduction. Nevertheless, Brazilian samples also cluster closely with a sample from Florida, which may suggest that the Brazilian population originated from lizards exotic elsewhere. High densities of adults and juveniles suggest that it comprises a well-established reproductive population in Brazil, thriving in urban and industrial areas. Introduction of A. porcatus may be related to the presence of a major seaport in the study region. Further assessments are needed to uncover whether this species will be able to expand into the surrounding Atlantic Rainforest, and whether it will impact the local communities, including native anoles. This study demonstrates the usefulness of molecular approaches for proper species identification in a group of aggressive invaders characterized by morphological conservatism, hybridization, and convoluted taxonomy.