LaFleur then was hired in 2008 by the Houston Texans to serve as an offensive assistant. He assisted both wide receivers and quarterbacks during his two-year stint there and developed a close relationship with offensive coordinator Kyle Shanahan.
Washington Redskins
When Shanahan's father Mike was hired by the Redskins, Kyle brought LaFleur to Washington to coach the quarterbacks in 2010. A primary responsibility of LaFleur's for the 2012 season was to mentor rookie quarterbacks Robert Griffin III and Kirk Cousins.
On February 5, 2015, LaFleur returned to the NFL as the quarterbacks coach for the Atlanta Falcons working under offensive coordinator Kyle Shanahan, with whom he had previously worked while with the Washington Redskins and Houston Texans. LaFleur's younger brother, Mike, was also an offensive assistant with the Falcons. In 2016, LaFleur coached Matt Ryan on his way to winning the NFL MVP. The Falcons reached Super Bowl LI, where they faced the New England Patriots, but squandered a large lead and lost in overtime.
Los Angeles Rams
On February 8, 2017, LaFleur joined the Los Angeles Rams coaching staff as offensive coordinator, working under head coach Sean McVay, with whom he had previously worked during his tenure with the Washington Redskins.
Tennessee Titans
On January 30, 2018, LaFleur left his position with the Rams to take the same position with the Tennessee Titans. Joining new head coach Mike Vrabel, LaFleur had the opportunity of calling the plays for the Titans, essentially a promotion from his former position as offensive coordinator with the Rams. LaFleur and the Titans finished the season with the 25th-ranked offense in the NFL.
Green Bay Packers
LaFleur was hired as the head coach of the Green Bay Packers on On May 30, 2019, LaFleur suffered a torn Achilles while playing basketball. LaFleur also led the Packers to a 2–2 preseason.
2019 season
On September 5, 2019, LaFleur made his regular-season head coaching debut against the Chicago Bears, and led the Packers to victory by a score of 10–3. He also became the first Green Bay coach to win his first game against the Bears since Vince Lombardi in 1959. The Packers finished with a 13–3 record in LaFleur's first season as a head coach, and in the process, LaFleur became the first Packers rookie head coach to win 10 games, make the playoffs, and win the NFC North. In addition, the 13 wins were the most from a rookie coach since Jim Harbaugh did it with the 49ers in 2011. LaFleur led Green Bay to their first postseason berth since the 2016 season, as he won his postseason debut against the Seattle Seahawks 28–23 in the divisional round of the playoffs to advance to the NFC Championship Game, where the Packers fell to the top-seeded San Francisco 49ers 37–20.