Taking to Twitter, Serena wrote: "@ashbarty, I can't lie I was sad to read your decision but also happy for your new chapter. Always your fan close up and afar. Sending all my love."
In a video posted on her Instagram account on Wednesday, Barty said that she was thankful for everything tennis gave to her and she called the time "right" to retire from the sport.
"Today is difficult and filled with emotion for me as I announce my retirement from tennis. I'm so happy, and I'm so ready and I just know at the moment in my heart as a person, this is right. I'm so grateful for everything that tennis has given me, it's given me all of my dreams plus more. But I know the time is now right for me to step away and chase other dreams and put the racquets down," she said in the video.
In her career, Barty won three Grand Slam titles -- the French Open in 2019, Wimbledon in 2021 and the Australian Open 2022.
Barty is also known for cricket skills and she showed the world what she is made of in the Women's Big Bash League while playing for the Brisbane Heat.
She on Thursday said that she will be removing herself from the WTA rankings after announcing her retirement, and this has paved the way for Poland's Iga Swiatek to become world number one provided she wins the Miami Open.