Indianapolis has a need for pass-rush help after the season-ending injury to DE Kemoko Turay.
Smith, 27, is a former first-round pick of the Eagles back in 2014. The Eagles declined to pick up his fifth-year option and eventually cut him loose during the summer in 2017.
Smith signed a one-year contract with the Seahawks soon after and finished out the year in Seattle. He re-signed with the Seahawks to a one-year contract worth up to $2.7 million, but was released during the preseason.
The Redskins signed Smith to a contract only to cut him loose soon after.
In 2017, Smith appeared in 14 games for the Seahawks and recorded 15 tackles, 2.5 sacks, two forced fumbles and a pass defense.