"It wasn't an easy draw for me so I am happy to get though," said Ivanovic, who didn't concede a set in the previous rounds against Yanina Wickmayer, Francesca Schiavone and Dominika Cibulkova. "I am still looking for more consistency."
The opening set against Voegele went with serve until Ivanovic broke her 58th-ranked opponent in the ninth game. Ivanovic dropped serve early in the second set but dominated the remainder of the match.
Voegele upset second-seeded Sloane Stephens of the United States in the quarterfinals.
Earlier, Kerber used two breaks for a 3-2 lead in the opening set against Suarez Navarro and didn't concede a game afterward. Kerber dominated with strong ground strokes, forcing Suarez Navarro to a total of 16 baseline errors.
"I feel better with every round," Kerber said. "Today I was more aggressive than in my previous matches."
The fourth-seeded Suarez Navarro, who hadn't lost a set getting to the semifinals, defeated Kerber in the fourth round of the U.S. Open last month.
Kerber was given a late wildcard entry in Linz to replace Kvitova after the former Wimbledon champion pulled out with a back injury. By reaching the semifinals, Kerber secured the eighth and final spot in the season-ending WTA Championships in Istanbul.