Ogletree, 26, was in the final year of his rookie contract and scheduled to become an unrestricted free agent in Mach.
"Alec has evolved into a true leader of our football team and we are excited to sign him to this extension," Rams General Manager Les Snead said, per the release. "His teammates voted him as a captain in back-to-back seasons for a reason—and it’s not only because of his production, but his character and resiliency. We look forward to Alec helping our team emerge as a consistent winner for years to come."
A first-round draft pick in 2013, Ogletree has solidified himself as a leader on the Rams' evolving defense alongside defensive tackle Aaron Donald.
Through 57 appearances—all of which have been starts—dating back to his rookie season, Ogletree has registered 330 solo tackles, 5.5 sacks and 11 forced fumbles. According to Pro-Football-Reference, Ogletree's 330 tackles are the ninth-most during that stretch.
Through five games this season, the Georgia standout has recorded 35 total tackles, a pair of pass breakups and two sacks.
With those stout second-level stylings locked up long-term, the Rams' next order of business will be finding financial middle ground with Donald following his training camp holdout.