After Kvitova beat unseeded Italian Sara Errani 6-4, 6-4, Sharapova set up a repeat of last year's final at the All England Club with a 6-2, 6-3 defeat of fellow Russian Ekaterina Makarova.
Kvitova beat Sharapova 6-3, 6-4 in their last Grand Slam meeting to claim her first major title.
"Obviously it was a tough one at Wimbledon," Sharapova said. "She's full of confidence and playing the best tennis right now. I look forward to it."
Three of the men's top four are already into the semifinals after Andy Murray ended the run of Japan's Kei Nishikori with a 6-3, 6-3, 6-1 win.
The No. 4-ranked Murray will face the winner of a later match between defending champion Novak Djokovic and David Ferrer of Spain.
Roger Federer and Rafael Nadal will meet for the 27th time in the other semifinal, scheduled for Thursday.
In men's doubles action, Toronto's Daniel Nestor and Belarusian partner Max Mirnyi reached the semifinals, defeating Santiago Gonzalez of Mexico and German Christopher Kas 6-1, 6-7 (4-7), 6-2.
Nestor, 39, has played in four Australian Open doubles finals and won the title with Mark Knowles of the Bahamas a decade ago.
"We came her to win the event," Nestor said. "We've gone this far but the matches are only going to get tougher.
"That's why we had the short off-season and came early to Brisbane. Hopefully we can win, it's been a long time for me here."
Nishikori, the first Japanese man to reach the quarter-finals here in the Open era, showed flashes of the form that earned him a surprise win over former finalist Jo-Wilfried Tsonga in the previous round.
During the first set, Nishikori played a lob shot through his legs on his way to winning the point — but by that time he was already a break down.
Murray, who hasn't dropped a set since the first round, broke seven times in all, although he plans to work on his serve after only landing 44 per cent of his first serves.
"The returning was good, so that was positive," said Murray, the beaten finalist the last two years here. "Could have served better, that's for sure."
In winning their quarter-finals, Sharapova and Kvitova also kept alive their chances of claiming the top ranking, which Caroline Wozniacki will vacate on Monday after her quarter-final loss to Kim Clijsters.
Sharapova must repeat her 2008 Australian title win. Kvitova only has to match or better the run of Victoria Azarenka, the only other player still in the running this week for the No. 1 spot.
Sharapova has dropped one set and lost 21 games en route to her first Australian Open semifinal since she won the 2008 final — the last of her three major titles.
"It's been a long road back to this stage," said Sharapova, who spent 10 months off court with a shoulder injury that required surgery.
Kvitova was far from her best against an opponent making her debut in a Grand Slam quarter-final, and with a 0-24 record against top 10 players. The second-seeded Czech made 44 errors and had to come back from a break down in the second set.
"I was a little nervous because I knew that everybody expect it will be easy match," Kvitova said. "Probably I had in my head that it's a good draw."