Kimberly Birrell is the no. 1 ranked Australian female professional tennis player.

As a 17-year-old, Kim burst onto the scene, reaching her first WTA Tour final at the Hobart International on the doubles court. Kim was rewarded with a wildcard into the Australian Open main draw in both singles and doubles. Following this breakthrough, Kim was called up to the Australian Fed Cup team, becoming the 48th woman to represent Australia in this prestigious competition.

In 2019, Kim made significant strides during the Australian summer of tennis, claiming her maiden top-10 win against Daria Kasatkina at the Brisbane International. Her performance earned her a wildcard into the Australian Open, where she advanced to the third round with notable victories over Paula Badosa and Donna Vekic.

Injuries sidelined Kim for the majority of the 2020 and 2021 seasons, but she made a strong return to the WTA tour in 2022. Kim's comeback was highlighted by her performance in the 2023 Australian summer of tennis, where she reached the second round of the Australian Open and broke into the top 150 in the rankings for the first time.

Kim's consistent performances throughout the 2023 season paid off when she broke into the top 100 in the WTA singles rankings for the first time in September, marking a significant milestone in her career.

A strong second half of the 2024 season saw Kim qualify for the main draw of the US Open, before reaching her maiden WTA Tour singles final in Japan.

Kim's career reached new heights in the 2025 Australian summer of tennis. She kicked off the season at the Brisbane International, where she reached the quarterfinals, claiming back-to-back top 50 wins including a top 10 win over Emma Navarro. She then qualified for the main draw of the Australian Open in singles and reached her maiden major final in the Mixed Doubles, partnering fellow Queenslander John-Patrick Smith. 

Following the Australian Open, Kim finished off her summer with a title at the ITF W75 tournament in Brisbane, reaching a career-high 75 in the WTA singles rankings and establishing herself as the no. 1 ranked Australian on the WTA singles tour.