The move, announced by Collins' agent on Twitter, reunites Collins with former Patriots defensive coordinator Matt Patricia, who is now the head coach of the Lions.
Collins, who turned 30 on October, had a productive season in his return to the Patriots in 2019, leading the team in tackles (80) and sacks (7). He played in every regular-season game, starting all but one, and had 81 tackles and three forced fumbles.
In a playoff loss to the Tennessee Titans, Collins was used in a backup/niche role, as the defense relied on more run-based defenders.
The 6-foot-3, 255-pound Collins, whose speed and athleticism contributed to the Patriots' playing more four-linebacker packages in the regular season, helped coin the nickname "Boogeymen" for the team's defense.
Collins entered the NFL as a 2013 second-round draft choice of the Patriots and was traded to the Cleveland Browns midway through the 2016 season. He returned to New England in 2019 on a modest, one-year deal that included a $150,000 signing bonus and $900,000 base salary.
In his seven NFL seasons, Collins has 576 tackles, 24.5 sacks, 16 forced fumbles, 6 recoveries, 10 interceptions and 2 defensive touchdowns.
ESPN's Mike Reiss contributed to this report.