Allison has agreed to a one-year contract for the veteran's minimum of $910,000, a source confirmed to ESPN. NFL Network first reported the terms of the deal, adding that Allison will also get a $137,500 signing bonus.
Allison spent the 2019 season with the Green Bay Packers, who had brought him back on a one-year, $2.8 million deal with the thought that he could move into the No. 2 wide receiver slot vacated by Randall Cobb. But Allison never took the jump they hoped.
Despite playing every game, Allison, 26, finished sixth on the team with 34 receptions and had four drops, according to ESPN Stats & Information.
He was on injured reserve during the 2018 season, undergoing surgery to repair a groin injury. He began that season as the Packers' No. 3 receiver and caught 20 passes for 303 yards and two touchdowns in five games. He also missed two games due to concussion.
The undrafted free agent signed with the Packers in 2016, catching 89 passes on 146 targets for 1,045 yards and 6 touchdowns.
Allison could end up being Detroit's No. 4 receiver -- or at least competing with Marvin Hall and Chris Lacy for the spot behind likely starters Kenny Golladay, Marvin Jones and Danny Amendola. Allison, though, doesn't have a ton of special-teams experience -- 232 snaps over four seasons in Green Bay -- which could be something to watch as he pushes for a roster spot.
It's possible the Lions could envision him like they did Jermaine Kearse last season before his season-ending injury -- a reliable veteran backup from whom they know what they can expect.
ESPN's Michael Rothstein and Rob Demovsky contributed to this report.