Quinn, 53, spent the last three seasons as defensive coordinator of the Cowboys. The Cowboys allowed the fifth-fewest yards and points this season. They ranked fifth against the pass and 16th against the run.
Quinn will fill the vacancy left by former Commanders coach Ron Rivera, who was fired Jan. 8. Rivera led the Commanders to a 26-40-1 record over four seasons.
The Cowboys defense ranked 12th, in terms of fewest yards allowed, in 2022 and 19th in 2021. They were 12-5 in each of the last three seasons, but failed to advance past the divisional round of the playoffs.
Quinn was head coach of the Atlanta Falcons from 2015 to 2020. He posted a 43-42 record with the Falcons, before being fired five games into the 2020 season, which they started 0-5.
The Falcons were 11-5 during 2016 and advanced to Super Bowl LI. Quinn's Falcons held a 28-3 lead until late in the third quarter of that game, before Tom Brady and the New England Patriots staged the largest comeback in Super Bowl history.
Quinn worked as Seattle Seahawks defensive coordinator in 2013 and 2014. The Seahawks allowed the fewest points and yards in the NFL over that span, led by an elite pass defense.
He also worked as the defensive coordinator at Florida in 2011 and 2012, overseeing an elite Gators defense. He started his NFL coaching career in 2001 as a defensive quality control coach with the San Francisco 49ers. He also spent time with the Miami Dolphins and New York Jets.
The Commanders vacancy was the last of this NFL head coaching hiring cycle, which started with eight openings. The Carolina Panthers, Los Angeles Chargers and Tennessee Titans also showed interest in Quinn.
The Commanders previously expressed interest in Eric Bieniemy, Aaron Glenn, Ben Johnson, Mike Macdonald, Raheem Morris, Bobby Slowik and Anthony Weaver.