The former Carolina Panthers defensive end reunites with Bills general manager Brandon Beane, head coach Sean McDermott and defensive line coach Eric Washington -- all of whom are familiar with Addison from their time with the Panthers.
After losing Shaq Lawson to the Dolphins on the first day of the legal tampering period, Buffalo moved quickly to find his replacement. Addison, 33, recorded 9.5 sacks in 2019 -- which would have tied for the lead among Bills players last season.
Addison, who turns 33 in September, has been the Carolina Panthers' sack leader the past four seasons with 39. He has 55 for his career, including 9.5 this past season. He was one of the biggest success stories of former coach Ron Rivera, who was fired with four games remaining last season.
Signed by Chicago in 2011 out of Troy as an undrafted free agent, Addison bounced between the 53-man roster and practice squads of the Bears, Colts and Redskins before being signed by Carolina off Washington's practice squad in December of 2012.
Considered undersized for an every-down end in a 4-3 scheme, the 6-foot-3, 254-pound Addison wasn't a full-time starter until 2017, when he started all 16 games. He responded with a career-best 11 sacks after signing a three-year, $22.5 million extension during the offseason.
Addison also flourished as an outside linebacker/end this past season after Carolina moved to a 3-4 base defense. His only missed start since 2017 came this past season after his 27-year-old brother, Gjamal Antonio Rodriqcus, was killed in his hometown of Birmingham, Alabama. Addison dedicated the rest of the season to his brother.
ESPN's David Newton contributed to this report.