Peko, whose deal is worth $7.5 million according to reports, is the second longtime Bengals lineman to leave Cincinnati in free agency, joining Andrew Whitworth, who signed with the Los Angeles Rams. Peko started all 16 games in nine of his 11 seasons with the Bengals. He had 37 tackles, three run stuffs and a fumble recovery in 2016.
He is joining his cousin, nose tackle Kyle Peko, in Denver.
Domata Peko has 517 career tackles, two forced fumbles and four fumble recoveries. During his career, Peko has also lined up as an extra blocker in the offensive backfield in short-yardage situations.
Kerr played 36 games in three seasons with the Indianapolis Colts, starting four times in both 2015 and 2016.
Poor play in the trenches cost the Broncos dearly last season as they failed to make the playoffs after winning the Super Bowl a year ago.
General manager John Elway added two offensive line starters Friday by signing free agents Menelik Watson and Ron Leary. Then he turned his attention to the defensive line.
The Broncos sorely missed Malik Jackson, who bolted to Jacksonville a year ago, and Vance Walker, who sustained a season-ending knee injury in training camp. Their inability to stuff the run or produce pressure from the middle negated their strengths: Von Miller rushing the passer and Aqib Talib and Chris Harris Jr. defending the pass.
The four free-agent signings, all of whom weigh more than 300 pounds, meet Elway's goal of filling his biggest needs in free agency so that he can go into next month's draft and focus on adding talent rather than plugging holes.
ESPN's Katherine Terrell and The Associated Press contributed to this report.