Barty added another sparkler to her collection when she revealed an engagement ring on Tuesday, having already landed the glistening Wimbledon trophy and an Olympic medal in the 2021 season.
She posted a picture of herself and Kissick on Instagram, showing off her ring and captioning the shot "Future Husband".
Kissick is a trainee professional at Brookwater Golf Club, a venue close to Brisbane, and is often seen in a Liverpool Football Club shirt, as was the case with the engagement picture.
He and Barty have visited Liverpool's home ground of Anfield together.
Speaking about having the likes of Kissick and coach Craig Tyzzer with her on the road, Barty said during her run to the Wimbledon title in July: "It's nice to be able to share some of these awesome moments with those that put so much time and energy into my career and allow me, encourage me, help me kind of work and figure out a plan and a way that they try and achieve our dreams. I think being able to share that with them is really special."
Barty won a bronze in mixed doubles at Tokyo 2020 alongside long-time friend John Peers, describing that achievement as "a dream come true".
She also won the Yarra Valley Classic, the Stuttgart Open, and WTA 1000 titles at Miami and Cincinnati before calling time on her season after a third-round exit from the US Open, where she lost to Shelby Rogers.
Barty finished the season as world number one for a third successive year, despite her recent inactivity.
She said a major triumph in her homeland was a priority for 2022, saying: "My focus is now on the Australian summer and doing everything I can to win the Australian Open. I can't wait to play at home again."