The 30-year-old Peterson leaves the Arizona Cardinals as one of the best cornerbacks in franchise history.
He went to eight straight Pro Bowls, starting with his rookie year in 2011 and ending in 2019 -- when he was ineligible because he was suspended six games for violating the NFL's performance-enhancing drug policy. Peterson is a three-time All-Pro.
Peterson's positional flexibility is a welcome asset for the Vikings secondary that featured two rookie starters in 2020 between Jeff Gladney, who lined up in the slot for 529 snaps last season, and Cameron Dantzler, a third-round pick who allowed the lowest passer rating in coverage among all rookie corners in the second half of the season (41.9 from Week 11-17).
With questions surrounding the health and future of 2018 first-round corner Mike Hughes, whose fifth-year option will likely be declined by Minnesota, Peterson gives the Vikings stability in the secondary coming off a season where he had seven pass breakups, his most since 2013. His three interceptions were his most since 2016.
Peterson has widely been considered one of the best cornerbacks throughout his career, known for his ability to defend the opposing offense's top receivers one-on-one on an island. He started all 128 games in the first eight seasons of his career before his suspension. In 2020, he was named to the 2010-2019 All-Decade Team by the Pro Football Hall of Fame.
Peterson played all 16 games last season and had 61 tackles and three interceptions. He has 28 interceptions in his career.
He entered free agency coming off a five-year extension signed in 2014. Peterson requested a trade in October 2018 during Arizona's dismal 3-13 season under former coach Steve Wilks, but he later apologized. However, reports of a fractured relationship between Peterson and the Cardinals' front office continued to circulate, which put his future with the franchise in doubt after his contract expired in March.
ESPN's Courtney Cronin and Josh Weinfuss contributed to this report.