She was a girls' singles semifinalist at the 2017 Wimbledon Championships, losing to eventual runner-up Ann Li. On the ITF Junior Circuit, Waltert had a career-high combined ranking of No. 9, achieved on 22 January 2018.
Waltert made her WTA Tour main-draw debut at the 2019 Ladies Open Lausanne, where she received a wildcard for the singles and doubles tournaments.1
She won her first doubles title at the 2021 Ladies Open Lausanne, partnering Susan Bandecchi.2
At the 2022 Ladies Open Lausanne, she earned her first top-10 win as a wildcard over world No. 7 and top seed Danielle Collins, saving three match points in the deciding tiebreak.345 By defeating Cristina Bucsa the second round, she went one step further to reach her first WTA Tour quarterfinal, where she was beaten by Olga Danilović.67 She won the 2022 Bronx Open in doubles with partner Anna Blinkova.
Waltert made her major debut at the 2023 French Open8 and won her first match defeating Elizabeth Mandlik,9 before losing in the second round to Elisabetta Cocciaretto.10 As a result, she reached a new career-high ranking of No. 107 on 12 June 2023.
Partnering with María Lourdes Carlé, Waltert was runner-up in the doubles at the WTA 125 2024 Montreux Nestlé Open, losing to Quinn Gleason and Ingrid Martins in the final which went to a deciding champions tiebreak.11
Only main-draw results in WTA Tour (incl. Grand Slam tournaments) are included in win–loss records.12
Current through the 2025 French Open.
Waltert's match record against players who have been ranked in the top 10.13
"Simona Waltert mit Wildcard in Lausanne". www.suedostschwiez.ch (in German). https://www.suedostschweiz.ch/sport/mehr-sport/2019-07-15/simona-waltert-mit-wildcard-in-lausanne ↩
"Zidansek battles past Burel in Lausanne to win first title". Women's Tennis Association. Retrieved 25 October 2024. https://www.wtatennis.com/news/2192278/zidansek-battles-past-burel-in-lausanne-to-win-first-title ↩
"Tennis, WTA – Lausanne Open 2022: Waltert downs Collins". Tennis Majors. 12 July 2022. https://www.tennismajors.com/wta-tour-news/lausanne-open-waltert-books-spot-in-second-round-612261.html ↩
"Lausanne: Waltert saves 3 MPS, upsets Collins for 1st Top 10 win". Women's Tennis Association. https://www.wtatennis.com/videos/2675948/lausanne-waltert-saves-3-mps-upsets-collins-for-1st-top-10-win ↩
"Collins stunned by home hope Waltert as Bencic bounces back in Lausanne". Yahoo. 12 July 2022. https://uk.sports.yahoo.com/news/collins-stunned-home-hope-waltert-200114947.html ↩
"Lausanne: Wildcard Waltert beats Bucsa in 3 sets to make 1st WTA QF". Women's Tennis Association. https://www.wtatennis.com/videos/2676859/lausanne-wildcard-waltert-beats-bucsa-in-3-sets-to-make-1st-wta-qf ↩
"Beginner's Guide: Simona Waltert breathes life into Lausanne with breakout run". tennis.com. https://www.tennis.com/baseline/articles/beginner-s-guide-simona-waltert-breathes-life-into-lausanne-with-breakout-run ↩
"Roland Garros 2023's Grand Slam debuts: Mirra Andreeva, Shymanovich, Waltert". Women's Tennis Association. https://www.wtatennis.com/news/3489256/roland-garros-2023-s-grand-slam-debuts-mirra-andreeva-shymanovich-waltert ↩
"Roland-Garros: Waltert beats Mandlik in battle of the qualifiers, into second round". Tennis Majors. Retrieved 25 October 2024. https://www.tennismajors.com/roland-garros-news/roland-garros-waltert-moves-into-second-round-684031.html ↩
"Roland-Garros: Cocciaretto makes third round". Tennis Majors. Retrieved 25 October 2024. https://www.tennismajors.com/roland-garros-news/roland-garros-cocciaretto-makes-third-round-685174.html ↩
"Begu takes traditional lake plunge after winning Montreux WTA 125". Women's Tennis Association. Retrieved 28 October 2024. https://www.wtatennis.com/news/4109391/watch-begu-takes-traditional-lake-plunge-after-winning-montreux-wta-125 ↩
"Simona Waltert | Player Stats & More – WTA Official". https://www.wtatennis.com/players/325771/simona-waltert ↩
"Head to Head". WTA Tennis. https://www.wtatennis.com/head-to-head/325771/ ↩