See main article: 2021 Challenger de Buenos Aires.
Guido Andreozzi and Andrés Molteni were the defending champions[1] but only Andreozzi chose to defend his title, partnering Thiago Seyboth Wild. Andreozzi withdrew from the tournament before his quarterfinal match.
Luciano Darderi and Juan Bautista Torres won the title after defeating Hernán Casanova and Santiago Rodríguez Taverna 7–6(7–5), 7–6(12–10) in the final.