See main article: article and 2021 Generali Open Kitzbühel.
Austin Krajicek and Franko Škugor were the defending champions,[1] but Krajicek chose to compete at the Summer Olympics and Škugor chose not to defend his title.
Alexander Erler and Lucas Miedler won the title, defeating Roman Jebavý and Matwé Middelkoop in the final, 7–5, 7–6(7–5).