Tolzien was a two-star recruit out of William Fremd High School, located in Palatine, Illinois, a suburb northwest of Chicago.

[12][13][14] Tolzien finished the 2009 season in a 20–14 win over Miami in the Champs Sports Bowl, completing 19 passes on 26 attempts as the Badgers knocked off the higher-ranked Hurricanes.

Most impressively, Tolzien led the Badgers down the field for the game-winning touchdown with Wisconsin's running game stifled by Iowa's defense.

[20] Tolzien made his final collegiate start at Wisconsin in the Rose Bowl against one of the top defenses in the nation, TCU.

[21] Tolzien won the Johnny Unitas Golden Arm Award in 2010, edging out finalists Andy Dalton of TCU, Colin Kaepernick of Nevada, Christian Ponder of Florida State, and Ricky Stanzi of Iowa,[22][23] In 2010, he set a new Wisconsin record for completion percentage in a single season, completing 74.3% of his passes in 12 regular season games.

[32] After Aaron Rodgers suffered a clavicle injury, the Packers brought him up from the practice squad to the active roster.

[33] In his regular season debut, Tolzien completed 24-of-39 attempts for 280 yards, one touchdown and two interceptions in a 27–13 loss to the Philadelphia Eagles, earning him the start in the Packers' next game against the New York Giants.

[35] The next week against the Vikings, Tolzien performed a spin move during a touchdown run before being relieved by quarterback Matt Flynn who led the Packers to a 26–26 tie against their divisional rival.

[40][41] Due to a concussion to Andrew Luck, Tolzien made his first start for the Colts on Thanksgiving on November 24, 2016, throwing for 205 yards, one touchdown, and two interceptions in a 28–7 loss to the Pittsburgh Steelers.

[42] With Luck being inactive due to a shoulder injury, Tolzien was named the starting quarterback to begin the 2017 season.

[45] On November 27, 2018, Tolzien was selected by the Birmingham Iron of the Alliance of American Football in the third round of the 2019 AAF QB Draft.

[46] Tolzien never played a down for the Iron as he retired before training camp began; the league would shut down abruptly eight weeks into its season.