The Miami Dolphins waived Jordan on March 31 after he failed a physical. The move saved Miami $3.225 million in salary for 2017.
Jordan projects as a strongside linebacker in the Seahawks' base defense and a defensive end in their sub packages. It would be a role similar to the one that Bruce Irvin filled for Seattle before signing with the Oakland Raiders in free agency last year. Mike Morgan, last season's starting strongside linebacker for the Seahawks, is an unrestricted free agent.
USA Today Sports first reported Jordan's agreement with the Seahawks.
In 2013, Miami made a trade and moved up from No. 12 to No. 3 to draft Jordan. He had just three sacks in 2013 and 2014 and has had multiple suspensions for violating the NFL's substance abuse policy. He didn't play in a game in 2015 or 2016.
The Dolphins kept Jordan under contract the past two years because of his potential. He was eligible to return from suspension in 2016 but arrived at training camp with a knee injury the team was unaware of. Jordan never showed Miami's coaching staff enough last season to get on the active roster.
Jordan, who turned 27 in March, was a star at Oregon from 2009 to 2012 under former NFL coach Chip Kelly.
ESPN's James Walker contributed to this report.