Coleman's agent, Blake Baratz, said Monday the deal was done. The Vikings have not yet made an announcement.
Coleman, a former seventh-round pick who started 27 games for the Philadelphia Eagles between 2011 and 2012, had been weighing his options since meeting with the Vikings last Friday.
Coleman likely would come in as a special-teams contributor and a backup at both safety spots, where he'd compete with Jamarca Sanford and Andrew Sendejo for playing time at one of them. He has averaged 42.5 tackles over a four-year career, but only had 13 last season.
ESPN NFL Insider Adam Schefter, ESPN.com Vikings writer Ben Goessling and The Associated Press contributed to this report.