"Here I come Packer Nation....Green and Yellow," he tweeted.
Hargrove also told ESPN.com of the deal later Thursday, and his agent told the Milwaukee Journal Sentinel that Hargrove had signed with the team. Hargrove visited with the Packers last week, league sources told NFL Network insider Jason La Canfora.
Hargrove has started just 25 games in his career. His highest sack totals came in 2005, when he started 15 games with the Rams and collected 6.5 sacks, and 2009, when he started six games and registered five.
Hargrove was a member of the Saints in 2009 and 2010, when then-defensive coordinator Gregg Williams ran a "bounty" program, according to the NFL. Williams and current Saints coach Sean Payton and general manager Mickey Loomis have been hit with suspensions by the league, but the NFL has yet to announce which individual players will be punished or how.
Hargrove was suspended for the 2008 season after violating the NFL's substance-abuse policy.