He played college football for the Temple Owls and was signed by the Indianapolis Colts as an undrafted free agent in 2013.

[1][2] As a senior in 2012, he earned All-Big East first-team honors after leading the team in scoring (74) on 14-of-17 field goals and 32-of-33 extra points.

[7] McManus was waived by the Broncos on November 11, 2014, after the team decided to sign free agent Connor Barth as his replacement.

[8] McManus cleared waivers, and was quickly re-signed by the Broncos, spending the rest of the season as the team's kickoff specialist.

[11] On September 13, 2015, he became the third kicker in NFL history to make multiple field goals of 56 or more yards in the same game, joining Sebastian Janikowski and Greg Zuerlein, who both achieved the feat in the 2012 season.

[17] In Super Bowl 50, he played a crucial role by making three field goals on three attempts and an extra point in the 24–10 victory over the Carolina Panthers.

[32] In Week 17, McManus kicked a career-long 61-yard field goal against the Los Angeles Chargers at the end of the first half.

[42] On October 20, 2024, in his first game with the Packers, he kicked a 45 yard game-winning field goal to help Green Bay defeat the Houston Texans 24–22.

[43] McManus kicked a 24 yard game-winning field goal to help Green Bay defeat his former team, the Jacksonville Jaguars 30–27 in his second game with the Packers on October 27, 2024.

[50] In September 2024, the NFL concluded its investigation into the incident, saying there was insufficient evidence to support a finding that McManus had violated the league's personal conduct policy.

[51] That same month, a judge dismissed the women's initial lawsuit, saying their case did not rise to the "exceptional" criteria required for anonymity.

[52] In October 2024, upon being signed by Green Bay, attorneys for both McManus and the accusers stated that the case was "resolved" without providing additional information.