Forsett and his agent sent out tweets indicating the move and sources confirmed it to ESPN's Adam Schefter.
— Justin Forsett (@JForsett) October 11, 2016
The 30-year-old Forsett worked out for the Lions earlier Tuesday before the signing. This will be Forsett's fifth team. After being drafted in the seventh round of the 2008 draft by Seattle, Forsett played in 102 games, gaining 3,697 yards and scoring 18 touchdowns for Seattle, Houston, Jacksonville and Baltimore.
Forsett spent the past two-plus seasons with the Ravens, including a career-best 1,266 yards and eight touchdowns in 2014. Forsett was cut by Baltimore earlier this month after losing his job to Terrance West.
He fills a need for the Lions in the backfield after the team lost starter Ameer Abdullah to injured reserve last month. Detroit also has rookie Dwayne Washington dealing with an ankle injury and he missed Sunday's win over the Eagles.
Forsett turns 31 on Friday.
The Lions have not announced the deal or a corresponding roster move.