Pierre-Paul is set to sign a one-year contract, a source told ESPN's Adam Schefter. The deal is pending a physical, and he is set to join the team next week.
"He wants to play, I know that," coach John Harbaugh said Friday after practice. "He's not coming in here to take a lot of time to get ramped up. I don't think that's in his mind right now. As soon as he looks like he's ready to go, he'll be out there."
This season, Baltimore has put two other outside linebackers on IR (Vince Biegel and Daelin Hayes) and lost Jaylon Ferguson, who died in June. Tyus Bowser, a starting outside linebacker last season, is on the physically unable to perform list and could return in a couple of weeks.
The Ravens' pass rush struggled Sunday in the 42-38 loss to the Miami Dolphins, which featured the biggest fourth-quarter collapse in team history. Baltimore has four sacks in two games this season.
The addition of Pierre-Paul comes after his second meeting with Baltimore. He visited the Ravens in June and left without a deal.
Ravens defensive coordinator Mike Macdonald on Thursday deferred questions about the signing of Pierre-Paul to general manager Eric DeCosta but said, "Obviously, JPP's had a great career. He's a heck of a player."
Pierre-Paul, 33, had 2.5 sacks in his fourth and final season with the Tampa Bay Buccaneers, during which he was hampered by a torn rotator cuff. He underwent shoulder surgery in February and was not re-signed by the Buccaneers in free agency.
When healthy in 2020, Pierre-Paul played a key role in the Buccaneers' championship run, registering a team-leading 9.5 sacks in the regular season and two in the NFC Championship Game.
A three-time Pro Bowl player, Pierre-Paul has totaled 91.5 sacks in 12 seasons.
ESPN's Jenna Laine contributed to this report.