The American mink (Neovison vison) has been introduced for fur farming into several countries around the world. In southern South America, although invasive populations have established in Argentina and Chile, no feral minks have been recorded in the Pampas Biome to date. We report a potentially new biological invasion in Uruguay, presenting observations, pictures and a museum specimen of feral minks in the locality Melilla, Montevideo Department, which probably escaped or were released from a local fur farm. We obtained 35 mink records between 2010 and 2020, mostly close to the fur farm, within a 2.5 km radius. Our report provides the northernmost mink records in South America, being the first in the Pampas Biome. American mink is a feared invader in most of the sites where it has been introduced, and therefore these new records are important mainly to plan and apply management interventions.