A former first-round draft pick from Cal selected in the 2003 NFL draft after the Ravens traded a first-round draft pick and a second-round draft pick to the New England Patriots, Boller spent last season with the Ravens on injured reserve due to a shoulder injury that required surgery.
"We are happy to add Kyle to our roster," Rams coach Steve Spagnuolo said in a statement. "We feel that he will be a valuable addition to our team."
In Baltimore, Boller was a polarizing figure who never lived up to high expectations because of a lack of consistency while drawing high marks for toughness and character.
With the Ravens, there was always the lingering question about whether former coach Brian Billick should have started Boller as a rookie, which seemed to hurt his development.
Ironically, former Ravens center Jason Brown took an inadvertent shot at Boller after Brown signed with the Rams as a free agent. Now, they’re on the same team again.
"Kyle Boller with the Ravens, I love him to death," Brown said during his introductory press conference in St. Louis last month. "But you see what getting hit one too many times early in your career can do to you. He became gun shy.
“Instead of getting the ball and standing back there with poise and then being able to step up, if there was a flash of anything, something, it might have been far on the edge, he was like … and he started to scramble."
In 42 career starts, Boller, 27, passed for 7,846 yards, 45 touchdowns and 44 interceptions.
In 2004, Boller started all 16 games and generated 2,559 yards, 13 touchdowns and 11 interceptions.
Boller was replaced by former Tennessee Titans quarterback Steve McNair and never reclaimed the job.
Boller had very thick skin, but took a ton of criticism from fans and the media during his time as Billick’s hand-picked starter.
Concluding his take on Boller, Brown emphasized that a quarterback has to believe in his line’s ability to protect him.
“You have to have the faith in your offensive line," Brown said. "To where you say, ‘Hey, I know these guys are going to give me the seconds that I need in order to get this ball off.’"