2021 Hamburg European Open – Women's singles
Kim Clijsters was the defending champion, having won the previous edition in 2002, but chose not to participate. Elena-Gabriela Ruse won her maiden WTA Tour singles title as a qualifier, defeating Andrea Petkovic in the final, 7–6, 6–4. This tournament marked Dayana Yastremska's return to professional tennis, after her suspension for testing positive for a prohibited substance was lifted by the ITF. Seeds. The top four seeds received a bye into the second round.