Hackenberg committed to Penn State after being recruited by a tandem of Penn State coaches – quarterbacks coach Charlie Fisher and running backs coach/recruiting coordinator Charles London, turning down offers from Alabama, UConn, Florida, Rutgers, South Carolina, Tennessee, and Virginia. Scouted as a five-star recruit by Rivals.com and a four-star recruit by Scout.com, Hackenberg was described as an accurate, drop-back passer with ample athleticism who has a high ceiling.
As a true freshman in 2013, Hackenberg was named the team's starting quarterback. In his first three games of the season, he twice earned Big Ten Conference Freshman of the Week accolades, with a 72-percent completion percentage, 851 yards, 4 touchdowns and 4 interceptions, including a game against Eastern Michigan in which he set the Penn State single-season record for passing yards by a freshman with 311 (previous record of 280 held by Zack Mills). Coach Bill O'Brien commended Hackenberg's leadership of the team, noting that the team feeds off his calm demeanor, in contrast to O'Brien's fiery personality. He did note that Hackenberg makes some mistakes typical of younger players, but he is on the fast track to grasping O'Brien's complex offensive schemes.
Hackenberg broke one Penn State overall and 11 school freshman game or season passing and total offense records this year, including game (30) and season completions (231), game (340) and season passing yardage (2,955) and game (4) and season (20) touchdown passes. He also broke freshman marks for game (55) and season passing attempts (392) and the number of 200-yard (9) and 300-yard (4) passing games.