Agent Brian Parker said the longtime Packers starter agreed to terms with the Rams on Friday after a free-agent visit there. Parker did not disclose terms of the deal.
The St. Louis Post-Dispatch reported that the deal was for four years and $24 million with $13 million guaranteed. Incentives could drive the worth of the deal up to $25.5 million.
Wells will give the Rams a veteran leader on their offensive line, continuing their offseason makeover under new coach Jeff Fisher. Wells' departure leaves the Packers searching for a replacement, which would likely come through free agency or the draft with no obvious candidate to replace Wells currently on the team's roster.
Wells has been the Packers' most consistent offensive lineman the past two seasons, and has played a critical role in dictating protections for Aaron Rodgers in one of the league's most productive offenses. Rodgers and Packers coach Mike McCarthy have routinely praised Wells' play in recent years.
He turned 31 in January.
Wells also visited the Tennessee Titans and drew interest from several other teams.
It's the continuation of a busy offseason for the Rams, who hired Fisher, made a mega-deal to trade the No. 2 overall pick in the draft to the Washington Redskins and signed cornerback Cortland Finnegan to a five-year, $50 million deal.
Wells, a seventh-round draft pick by the Packers out of Tennessee in 2004, has started 100 regular-season games.
With Wells leaving, the only two centers on the Packers' roster are Evan Dietrich-Smith, an interior lineman who is best known for being on the receiving end of Ndamukong Suh's infamous stomp on Thanksgiving, and inexperienced backup Sampson Genus.
Free-agent options who may draw interest from the Packers include Indianapolis Colts veteran Jeff Saturday; New England Patriots center Dan Koppen, who is returning from an injury; and Oakland Raiders free agent Samson Satele.