Leary, the ACC preseason player of the year, suffered the injury against Florida State last week.
"Additional imaging caused NC State's orthopedic team to determine that surgery to a torn pectoral muscle was the best course of action," the school said in a statement Saturday. "There is no damage to his shoulder and he is expected to make a full recovery."
Leary's surgery will be performed by Dr. James Andrews next week in Florida, the statement said.
Leary, a fifth-year player, is one of the most accomplished quarterbacks in the sport. He has thrown for 6,807 yards and 62 touchdowns in his career with 11 touchdowns and four interceptions this season.
NC State will start Jack Chambers, a graduate transfer from Charleston Southern who arrived in 2022 and has yet to start a game for the Wolfpack. Chambers did not complete a pass in relief against Florida State but did lead the Wolfpack on a pair of fourth-quarter field goal drives that allowed them to take the lead and win the game.
Chambers did flash a dual-threat capability, finishing the game with 39 rushing yards on seven attempts. He failed to complete the only pass he threw. On the season for NC State, he is 6-for-14 for 48 yards and one touchdown. This will be his first start for the Wolfpack.
At Charleston Southern, Chambers was second-team all-Big South and finished in the top 20 nationally in the FCS with 63.3% completion rate.
Leary left last week's game after taking a hit from 300-pound Florida State defensive lineman Joshua Farmer late in the third quarter of NC State's win. Farmer was penalized for roughing the passer on the play. Leary eventually left the field with the help of trainers and watched the final quarter with his right (throwing) arm in a sling.
Leary entered the season as one of the most intriguing players in the sport, as he'd thrown 35 touchdowns and just five interceptions in 2021. That earned him plenty of preseason college hype and NFL intrigue, as his arm strength was considered among the best in the sport by NFL scouts.
Leary was so bullish on the Wolfpack before the season that he predicted this could be one of the school's best-ever teams. "I think it could be the best team," Leary told ESPN this summer, "to ever come through NC State."
The Wolfpack (5-1) will face a Syracuse (5-0) defense that's one of the surprise units in the country. The Orange are Top 10 nationally in scoring defense (14.0 ppg) and total defense (271.6 ypg), as coordinator Tony White's unorthodox 3-3-5 has given up more than 20 points only once in five games.
This is the first time two ranked teams are playing at Syracuse since 2001.