The 21-year-old, who becomes the first Czech to win the title since Jana Novotna in 1998, served out the match to love with her first ace of the day on championship point.
Kvitova had never won a match on grass before her surprise run to the semi-finals at the All England Club and becomes just the third left-hander to win the title after Ann Jones and Martina Navratilova.
Kvitova looked anything but nervous in her first major final as she out-hit and out-manoeuvred Sharapova, making just 13 unforced errors during the 85-minute match.
"I'm so happy," the tearful champion said in an on-court interview before blowing a kiss to Novotna and Navratilova watching from the Royal Box.
"I was nervous but I had to focus on every point."
Sharapova, who also won her first Grand Slam title at Wimbledon, as a 17-year-old in 2004, won the toss and opted to receive, a tactic that looked to have worked well as she immediately broke the Kvitova serve to get off the mark.
But the eighth seed, who also beat world number four Victoria Azarenka in the semi-finals, bounced back straight away, with a series of blistering forehands that left Sharapova flailing on the baseline.
That early wobble out of the way and the rest of the set was one-way traffic as Kvitova broke once again in the sixth game when Sharapova, wary of her opponent's return of serve, slapped down consecutive double faults.
Sharapova also opened her next service game with a double fault before handing Kvitova a set point with a forehand into the net.
The Russian did manage to save it, with her first ace of the match, but could do nothing about the Czech's serve when Kvitova stepped up to serve out the first set, sealing it with a body serve at the first attempt.
The second set was more of a topsy-turvy affair with Kvitova tightening up slightly after storming to a break in the opening game having rattled a forehand winner down the line.
Always a fierce competitor, Sharapova forced her way back into the match, breaking back in the fourth game with an inch-perfect lob.
With serving by far Sharapova's biggest weakness, especially since her career-threatening shoulder injury, the Russian promptly handed Kvitova the break back, the 21-year-old snatching the game with yet another forehand winner.
The two traded another break apiece before Kvitova could eventually regain her rhythm on serve, holding to leave herself just one game away from the title.
Sharapova also re-discovered her first serve when it really mattered, holding to love to force Kvitova to serve for her first Grand Slam title.
But any hopes the Russian might have had that Kvitova would get nervous and stumble at the last hurdle were roundly dismissed as the Czech quickly earned herself three match points with three huge serves before firing her first, and only, ace of the day down the centre of the court before sinking to her knees on the realisation she had won the title.