The extension is worth $58 million, with $34 million guaranteed, a source confirmed to ESPN. NFL Network first reported the financial terms.
A league source said Griffen's $34 million is guaranteed for injury at signing, so it's not all fully guaranteed at this point.
Griffen, 29, has two years remaining on his current contract with base salaries of $6.9 million in 2017 and $8.4 million in 2018. The extension begins in 2019.
"I mean it means I am a Viking for life and my appreciation is high man and I appreciate each day I step onto the football field," Griffen said of the extension.
"I appreciate the coaching staff and the organization. It just shows me that they respect me more as a player than a man and I can't take that for granted. I have to go out there and play balls to the wall now like I always do. I don't have to change my game now but I'm going to take it to the next level each and every day and help this team win."
He has started all 47 games he's played in the past three seasons and has 30.5 sacks during that time, including eight last season.
He has been selected to the Pro Bowl each of the past two seasons.