The 49ers and ex-Vikings S Madieu Williams have agreed on a one-year deal, agent Kenny Zuckerman told PFW Monday.
Matt Maiocco of Comcast Bay Area first reported the news of Williams' agreement with the Niners.
Williams started 13 games for Minnesota last season, notching 75 tackles. The Vikings let him go last week. He's expected to contend to start in San Francisco. DaShon Goldson, the Niners' starter at free safety last season, is currently an free agent.
Williams, 29, played for Cincinnati from 2004-07 before joining the Vikings in '08.