The top-seeded Barty, who won the French Open in 2019, became the first Australian woman to win the Wimbledon title since Evonne Goolagong in 1980.
Pliskova was seeking her first Grand Slam title. She also lost in the US Open final in 2016.
The eighth-seeded Pliskova didn’t win a single point in the first three games of the first set and then double-faulted on break point to hand Barty a 4-0 lead. She finally held serve for the first time to make it 5-3 before Barty served out the set.
Things were tighter in the second set before Barty broke Pliskova in the match’s first deuce game to take a 6-5 lead. But Pliskova broke back to force the tiebreaker — the final’s first since Venus and Serena Williams in 2009 — and then the first deciding set in the Wimbledon women’s final since 2012, when Serena Williams defeated Agnieszka Radwanska.
Barty, who improved to 6-2 in career meetings with Pliskova, found her form again in the third set, racing out to a 3-0 lead before closing out the match and championship on serve.
Both women were making their first appearance in a Wimbledon final, the first time that had happened since 1977, when Virginia Wade defeated Betty Stove.
Information from The Associated Press was used in this report.