Onyemata's deal is worth $27 million over three years, as first reported by the NFL Network, with $18 million guaranteed, a source told ESPN.
There is a fourth year that will automatically void for salary-cap purposes, the source said.
Onyemata, 27, has been a big reason for the resurgence of New Orleans' run defense, which led the NFL over a two-year span from 2018 to 2019, allowing just 85.8 rushing yards per game. But he also has enough athleticism for his size to aid in the pass rush, compiling 9.5 sacks over the past three seasons.
He has quietly developed into one of the Saints' many great draft finds in recent years.
A native of Nigeria, the 6-foot-4, 300-pounder never played football until he was at the University of Manitoba in Canada. The Saints traded up to draft him in the fourth round in 2016, and he has played nearly 60% of the defensive snaps over the past three years. He started all 16 games he played in 2019, including the playoffs.
Onyemata was suspended for one game to start the 2019 season after being issued a misdemeanor summons for marijuana possession.
The Saints are also finalizing a deal with long-snapper Zach Wood that is expected to be worth $4.78 million over four years, with $1.3 million guaranteed, a source said.