The reigning Wimbledon champion, who has never been beyond the fourth round at Flushing Meadows, took less than an hour to see off her French opponent.
Kvitova started strongly and broke Mladenovic at the first time of asking to move into a 3-0 lead in the opening set.
The Czech remained dominant on her own serve, winning 85 per cent of points on her first, and 83 per cent on her second.
A further break arrived in game six, while Kvitova recorded seven winners in the first set and Mladenovic failed to make one.
The second set followed a similar pattern, with world number 73 Mladenovic struggling to find any rhythm on her own serve, producing five double faults.
Once again, Kvitova made her first serve count as the world number four and third seed romped to an easy victory and booked a place in the second round.