The men's doubles of the 2021 I.ČLTK Prague Open tournament was played on clay in Prague, Czech Republic.

Pierre-Hugues Herbert and Arthur Rinderknech were the defending champions[1] but chose not to compete this year.

Marc Polmans and Sergiy Stakhovsky won the title after defeating Ivan and Matej Sabanov 6–3, 6–4 in the final.