Lilli Tagger (born 17 February 2008) is an Austrian tennis player. She has a career-high WTA singles ranking of world No. 109, achieved on 21 March 2026. Tagger was the 2025 Junior singles French Open champion.
From Lienz, she later became based in Varese near Milan, in Italy, and trained at the academy of Francesca Schiavone.
In July 2024, she qualified for the girls' singles at the 2024 Wimbledon Championships with a win over Ksenia Efremova in a 10âÂÂ6 match tiebreak.
She beat Mimi Xu to reach the quarterfinals of the girls singles at the 2025 Australian Open where she lost to Australian Emerson Jones.
At the 2025 French Open she had Francesca Schiavone as part of her support team. She reached the semifinals of the girls' singles with a win over the number 12 seed Julia Stusek. In doing so, she became the first female Austrian player to reach the semifinals of a junior Grand Slam tournament since Tamira Paszek in 2006, and the first Austrian overall since Dominic Thiem in 2011. Tagger again faced Emerson Jones and won in straight sets, before also defeating Hannah Klugman of Great Britain in straight sets, for the loss of only two games in the final. In the girls' doubles she played alongside Slovakian Mia Pohánková and they reached the semifinals before facing German pairing Sonja Zhenikhova and Eva Bennemann.
In November 2023 Tagger reached her first ITF Women's Circuit final in Sharm El Sheik. She won her first ITF tour doubles title in Viserba, Italy in July 2024 playing alongside Italian Anastasia Bertacchi, they defeated Francesca Pace and Inès Ibbou in the final.
In December 2024, she played in her first WTA 125 tournament main-draw in Limoges as a wildcard entrant, where she won her first round match against the world No. 159, Victoria Jiménez Kasintseva, before losing in the second round to sixth seed Nuria Parrizas-Diaz.
In March, Tagger won her first ITF Circuit singles title defeating Lois Boisson in a straight-sets final in Terrassa, Spain.
In October, Tagger was given a wildcard entry to make her WTA Tour debut at the Jiangxi Open, recording wins over fellow WTA debutante Zhu Chenting, Elisabetta Cocciaretto and Tamara Korpatsch to make it through to the semifinals, where she fought back from three match points down to overcome second seed and defending champion, Viktorija Golubic, in three sets to become the first player born in 2008 to reach a WTA Tour final. In the championship match she lost to Anna Blinkova in straight sets. Despite her defeat, she reached a new career-high ranking in the top 200 at world No. 156, on 3 November 2025.
In March, she was able to compete in the main draw of a WTA 1000 tournament for the first time, after receiving a wildcard at the 2026 BNP Paribas Open in Indian Wells. In the first round, she defeated French Varvara Gracheva in straight sets in 82 minutes. In the second round, she was defeated by world No. 34 Maria Sakkari.
At the 2026 Miami Open where she also received a wildcard for her debut at the event, she defeated qualifier Ella Seidel.
Tagger plays with a single-handed backhand.