In her third straight final at the WTA Premier hard-court event, the Wimbledon champion's 6-4 6-2 victory over Magdalena Rybarikova saw a repeat of her 2012 title win.
Serena Williams, who won the Western and Southern Open last weekend, has had a week of rest to prepare for the final grand slam of the year starting Monday, but Kvitova played herself back into form having lost in the second round in Cincinnati.
Simona Halep and Eugenie Bouchard had both hoped to do the same but they exited the tournament early while Kvitova, the second seed, got through her four matches without dropping a set.
Having won the final in 69 minutes in New Haven, the 24-year-old will hope it gives her the momentum at Flushing Meadows, where she has never progressed past the fourth round.
Slovak Rybarikova, playing in her first final of the year, started well but failed to convert an early break chance that could have set her on the way to another upset, having already beaten Halep.
Instead it was Kvitova who picked up the first break in the sixth game, but she appeared nervous as she went on to waste two set points to allow Rybarikova back into the match.
Luckily for the world number four, she broke again in the 10th game to take the set.
The second set was much more routine for Kvitova, who lost just four points on serve.
Having seen the first five games go with serve, the Czech lifted to win the final three games and take the title.
Kvitova's attentions will now turn to Frenchwoman Kristina Mladenovic, who she faces in the first round at the US Open, while Rybarikova will meet Denmark's Caroline Wozniacki.