We report new records of the Arctic Tern Sterna paradisaea Pontoppidan, 1763 for the coast of Rio Grande do Sul, southernmost Brazil. Birds were in first alternate plumage, apparently overwintering in the region. A literature and museum review revealed the existence of 21 localities with records of this species in Brazil. Ten specimens were obtained in the country, attributable to eight localities. Records from five other localities were documented with band recoveries or photographs. We were able to clarify information from one of the undocumented records, while the remaining requires further investigation and/or documentation. Our review and new information on migration routes confirm that the Arctic Tern in Brazil is a regular, seasonal visitor from the northern hemisphere. We also suggest that waters off south Brazil may be used by overwintering individuals, especially during the austral winter.