A source told ESPN's Adam Schefter that the five-year extension is worth $92.5 million with $49 million guaranteed. O'Neill, who was entering the final year of his rookie deal, is now contractually tied to the Vikings through the 2026 season.
"Earlier this offseason when I said, 'I want to be here, no matter what.' I've known that for a long time," O'Neill said. "The people we have in this building, everybody around here, I just want to be a part of it. And I'm happy to be a part of it. There was never really a doubt as to whether or not something was going to work or not, in my mind. Because this is where I want to be. I want to be a Viking for my whole career."
O'Neill was drafted by Minnesota in the second round in 2018 and has appeared in 46 career games and has never missed a start because of injury. The Vikings have the third-most rushing yards in the NFL (4,416) since O'Neill won the starting right tackle job six games into his rookie season.
Minnesota has used six draft picks on offensive linemen in the first three rounds dating to 2017. O'Neill is the oldest and most accomplished from that group.
"It means a lot just because they believe in me, but at the same time, it means I have to go prove it, just like I had to go prove it when they drafted me," O'Neill said. "I've got to prove them right. They believe in me just like they did three years ago, but it's time to go prove them right again. The chip just gets bigger."
The 26-year-old O'Neill ranked first among all offensive linemen in run block win rate at 80.5% last season, according to research by ESPN Stats & Information and NFL Next Gen Stats. He was 26th among tackles in pass block win rate.
Collectively, the Vikings were 18th in pass block win rate in 2020 after allowing 39 sacks. Coach Mike Zimmer pointed out several "unknowns" with the current offensive line with new starters at right guard (Oli Udoh), left guard (Ezra Cleveland) and veteran Rashod Hill starting at left tackle while rookie first-rounder Christian Darrisaw slowly returns to practice after missing training camp with a groin injury.
Despite the turnover, O'Neill expressed confidence in his group as it prepares to face Cincinnati in Sunday's regular-season opener.
"I think we're in a good place," O'Neill said. "I think we're in a really good place. I'm really, really excited to play next to Oli. I think he's done an unbelievable job; I'm really proud of him for the strides he's made. I think a lot of people are going to be really happy with Oli, and Garrett [Bradbury] leads the show. He's done an unbelievable job for us, and his communication's been on point. Ezra's only getting better, and Rashod has always been able to hold it down out there.
"I love our group, I love our coach, I love our assistant coach. We've got a great room, and this is the most excited I've been about an offensive line here. I think, hopefully, we'll be able to see the results, but we've got to go out and be able to prove it. We've got to go out and prepare today in order to have success on Sunday."
With O'Neill's new deal on the books, the Vikings have successfully ironed out two contract extensions on the eve of the 2021 regular season. Minnesota gave 32-year-old safety Harrison Smith a four-year, $64 million extension at the end of the preseason.