The 31-year-old baseliner was not quite firing on all cylinders as she continued her preparations for the Australian Open after a lengthy break, but had enough quality and experience to get past her aggressive 24-year-old opponent.
"It feels amazing to win another title especially after a not great end to last season," said Ukrainian Svitolina, three times a quarter-finalist at Melbourne Park.
"It was nice to get tough matches here this week and win the final, hopefully we can build on that for the rest of the season."
Wang, playing her second WTA final but still seeking her first title, troubled Svitolina early on with some deep groundstrokes and well-executed drop shots but too often allowed the world number 13 off the hook with some simple errors.
Watched from the sidelines by husband Gael Monfils, Svitolina broke for 4-2 on the back of a Wang error and served out with an ace to seal the opening set three games later.
World number 57 Wang had three break points in the fourth game of the second stanza but top seed Svitolina found her first serve when it mattered to get out of trouble.
Breaking Wang again proved a tougher task and the match was decided in a tiebreaker, Svitolina digging deep to rally from 3-0 down and make some amends for losing to Coco Gauff in the 2024 final.