Aryna Siarhiejeŭna Sabalenka was born in Minsk, the capital of Belarus. Her father, Sergey, was a hockey player, and he introduced her to tennis at a young age.

Sabalenka began training in tennis at a relatively young age, developing her powerful groundstrokes and aggressive playing style. Information about specific junior tournaments and coaches during this period is limited.

Sabalenka began competing on the ITF Junior Circuit. She achieved a relatively modest junior ranking, with a best of No. 225, indicating that her focus quickly shifted towards professional play.

By 2016, Sabalenka began focusing primarily on professional tournaments, signaling her intent to pursue a career at the highest level of the sport. She quickly started climbing the WTA rankings.