The deal includes $22 million guaranteed, a source said.
Ngakoue, who turns 26 on March 31, is a highly regarded disruptive pass-rusher who had a hectic 2020 season, receiving the franchise tag from the Jacksonville Jaguars after contract talks broke down before getting traded to the Minnesota Vikings and, later, the Baltimore Ravens.
This past season, Las Vegas ranked 29th in the NFL with 21 sacks, and it allowed opposing quarterbacks to hold the ball for 2.86 seconds before the pass, the fourth-highest rate in the league.
The agreement also reunites Ngakoue with new Raiders defensive coordinator Gus Bradley, who was his coach in Jacksonville.
Ngakoue is one of four players since 1982 (when sacks became an official stat) to begin his career with five consecutive eight-plus sack seasons, totaling 45.5. He also has 18 forced fumbles, which rank second in the NFL behind Khalil Mack (20) over that same period.
The Ravens thought they were adding the final critical piece to their defense when they traded a 2021 third-round pick and a 2022 conditional fifth-rounder to the Vikings for Ngakoue in October, but he never really clicked in Baltimore, finishing with 11 tackles and three sacks in nine games. Ngakoue only played 20 snaps in the AFC divisional playoff loss to the Buffalo Bills, although coach John Harbaugh said Ngakoue's role would've changed if he returned.
Baltimore could've kept Ngakoue by placing the franchise tag on him, but the $15.89 million cost would've taken up most of the Ravens' cap space. The Ravens will recoup a compensatory pick in the 2022 draft.
A third-round pick by Jacksonville in 2016, Ngakoue reached the Pro Bowl in his second season after recording a career-high 12 sacks. However, he became unhappy with the Jaguars after negotiations on a new contract ended before the 2019 season. The next year, Jacksonville put the franchise tag on Ngakoue, who then went on a Twitter tirade against Tony Khan, the son of owner Shad Khan and the team's senior vice president of football administration and technology.
In August 2020, Ngakoue was traded to the Vikings for a 2021 second-round draft pick and a conditional 2022 fifth-rounder. He recorded five sacks, two forced fumbles, seven quarterback hits and 12 tackles (five for losses) in six games for Minnesota, but the Vikings stumbled to a 1-5 start and decided to trade him to the Ravens.
Information from ESPN's Jamison Hensley and Paul Gutierrez was used in this report.