The Seahawks announced the signing Thursday night. The team reports for training camp Friday, with the first practice scheduled for Saturday morning.
Bryant had a tryout with the Seahawks during June's minicamp. Coach Pete Carroll said he didn't feel Bryant was in football shape then and wanted to see if the veteran could get himself ready in the month between the June tryout and training camp.
Bryant hasn't played since the 2009 season with the Tampa Bay Buccaneers. He signed a four-year, $28 million with the Cincinnati Bengals before the 2010 season, but he was cut at the end of training camp and spent the past two seasons out of the NFL.
The Associated Press contributed to this report.