The team announced the move Monday along with the release of wide receiver Brian Robiskie.
Hope started 113 of 163 games and had 20 career interceptions over 11 seasons with Pittsburgh, Tennessee and Atlanta. He started in four games last season for the Falcons and played in both of their playoff games.
The Lions likely added Hope, a Pro Bowl player in 2008, because they're not sure safety Louis Delmas can stay healthy enough to be counted on next season.
Robiskie had four receptions for 44 yards and a touchdown in six games with the Lions last season. He caught 39 passes for 441 yards with three touchdowns from 2009 through 2011 in Cleveland.