Davis agreed to a one-year deal Tuesday with the Redskins, announcing the signing on his Instagram account and saying he was "Reunited with my guy," meaning Rivera, who became the Redskins' new coach after the 2019 season.
A team official confirmed the signing to ESPN.
Davis, who was released last week by the Los Angeles Chargers, spent 14 years with the Carolina Panthers, including eight when Rivera was in charge. Davis was a standout player with Carolina, making three Pro Bowls and earning first-team All-Pro honors in 2015.
Davis has played weakside linebacker, an area of need for Washington. The Redskins agreed to terms with linebacker Kevin Louis-Pierre earlier Tuesday, but he's viewed more as a backup at both outside spots and a standout special-teamer. They also have Cole Holcomb, who likely will start at strongside linebacker.
Reuben Foster continues to recover from a torn ACL and nerve damage in his foot suffered on the first day of 2019 OTA workouts. The Redskins remain uncertain when he'll be available.
Last season, Davis started all 16 games and led the Chargers with 112 tackles -- the third-highest total in his career. He also had one sack.
Davis had said in January 2018 he would play one more season. Several months later, he was suspended four games for violating the NFL's policy on performance-enhancing drugs. After the season, he wanted to keep playing and announced he would not return to Carolina. He then signed a two-year deal with the Chargers.
Davis has recorded 1,210 career tackles, 29.5 sacks, 13 interceptions and 18 forced fumbles.