The deal is for $14 million and includes $8 million that is fully guaranteed, a source told ESPN's Adam Schefter.
Villanueva, 32, started at left tackle for the Pittsburgh Steelers for the past six seasons but would fit in with the Ravens' supersized offensive line on the right side. He ranked 18th last season in run block win rate -- three spots higher than Brown (21st) -- which should fit in with a Baltimore offense that ran the ball on a league-high 50.3% of plays from scrimmage last season.
The Ravens also get a safety net for left tackle Ronnie Stanley, who is coming off a season-ending ankle injury and hasn't played a full 16-game season in his five-year career. Villanueva made 90 starts at left tackle from 2015 to 2020 and reached the Pro Bowl in 2017 and 2018.
This potentially gives Baltimore one of the most formidable-looking offensive lines in the league with left tackle Stanley (6-foot-6, 315 pounds), left guard Ben Cleveland (6-6, 357), center Bradley Bozeman (6-5, 325), right guard Kevin Zeitler (6-4, 315) and right tackle Villanueva (6-9, 320).
By signing Villanueva after Monday, he will not cancel out any of Baltimore's compensatory picks. The Ravens are in line for two fourth-round comp picks in the 2022 draft after losing Matthew Judon and Yannick Ngakoue in free agency.
The Colts and Dolphins also had shown interest in Villanueva, sources told ESPN.
Villanueva is a former Army Ranger who served two tours in Afghanistan. He was part of two divisions, 10th Mountain and 75th Ranger Regiment, before becoming an NFL player.
He signed a four-year contract with Pittsburgh in July 2017, and he was a Pro Bowl selection in 2017 and 2018, during which time the Steelers' offensive line ranked among the league's best after giving up just 24 sacks each season. In his six seasons on the active roster, Villanueva started 90 of the 96 games in which he appeared.
One of the more recognizable offensive linemen in the league became part of the national anthem debate in 2017 when he became unintentionally separated from the team in Chicago as he tried to catch a glimpse of the flag during the national anthem. The team had previously decided to stay in the Soldier Field tunnel during the anthem, and Villanueva ended up standing alone outside the tunnel.
During the 2020 season, Villanueva again became part of a debate after he covered up the name of a police shooting victim on the back of his helmet with the name of a deceased Black Army Sgt. 1st Class whom he believed deserved the Medal of Honor for rescuing six soldiers from a burning vehicle in Iraq.
ESPN's Brooke Pryor contributed to this report.