It is the first time that Federer has met Wawrinka in Switzerland and Federer reached the semis with a straight sets win over Andy Roddick in Friday's quarter-finals.
Federer's 6-3 6-2 win was his 21st over Roddick in 23 matches on the tour, with the American never really looking like he believed he could win.
"We’ve played on so many occasions that sometimes you can’t play your best, and that’s what happened to Andy today," said the Swiss Maestro afterwards.
"He didn’t have a very good serving day and then once I get a chance to get into all his service games, it’s always going to be difficult for him to find a way."
Wawrinka was in superb form in the quarters, dropping just nine points on serve as he cruised past Florian Mayer, 6-2 6-2. It was a one-sided match, with Wawrinka overwhelming the German with his aggressive tennis.
Federer knows he faces a difficult test later today.
"This is the first time I’ve played Stan here in Switzerland," he said.
"We’ve faced off together 10 times and playing back in Switzerland is particularly special because I come from this town and Stan’s not too far away either.
"I think it’s a special occasion for Swiss tennis and the Swiss fans. He played incredibly well today, so I think this is going to be the test of the tournament for me so far."
This could be an extremely entertaining matchup.
Prediction: Federer in three.