Williams started 171 games over 11 seasons with Minnesota, earning six Pro Bowl selections to tie him with John Randle for second in team history behind Alan Page. He recorded 60 of his 63 career sacks with the Vikings.
"I had a great time with the Vikings and appreciate them giving me a chance," Williams said. "They drafted a small town kid from Arkansas and the organization, the city, the whole state really, helped raise me into a man. I appreciate them for that and look forward to coming back and doing some things with the team."
Minnesota general manager Rick Spielman was quick to applaud Williams for his contributions to the franchise.
"Kevin was one of the most respected players in Vikings history by his teammates and by opponents," Spielman said. "He set a high standard for himself and led by example instead of words. We thank him for everything he gave the Vikings and the legacy he leaves."
Williams wrapped up his career by playing with Seattle in 2014 and making 14 starts with New Orleans in the following campaign.
The ninth overall selection of the 2003 draft, Williams collected 525 tackles, five interceptions and nine forced fumbles during his 13-year career.