Hyder's agent, Erik Burkhardt, relayed the news to ESPN's Adam Schefter.
Per Pro Football Talk's Charean Williams, Hyder's deal is essentially a two-year, $6.5 million contract. The third year has a voidable $10 million base salary.
Bob Condotta of the Seattle Times explained where Hyder may fit in the Seahawks defense while also noting the move doesn't necessarily prevent the team from bringing back defensive end Carlos Dunlap, who is a free agent.
"My understanding is Seattle plays to use Kerry Hyder mostly at the 5-tech spot and not at the LEO position. So it doesn't necessarily preclude bringing back Carlos Dunlap," Condotta wrote.
Hyder, who turns 30 years old in May, amassed a career-high 8.5 sacks and 49 tackles for the 49ers in 16 games last season. He got the opportunity to start beginning in Week 3 after defensive linemen Nick Bosa and Solomon Thomas suffered season-ending injuries in Week 2. Hyder took over in the starting lineup and never looked back en route to leading the 49ers in sacks.
The former Texas Tech Red Raider has taken the field in five NFL seasons (2015-2016, 2018-2020) with the Detroit Lions, Dallas Cowboys and 49ers. Last season marked his first year as a full-time starter. He got in a lot of work in 2016 with the Lions, however, en route to eight sacks.
The Hyder news is in addition to another report from ESPN's Brady Henderson that the Seahawks have signed defensive end Benson Mayowa to a two-year deal. Mayowa was third on the Seahawks with six sacks last year.