A league source told ESPN NFL Insider Adam Schefter that Cribbs signed a one-year deal.
Since being released by the Cleveland Browns earlier this offseason, the three-time Pro Bowler had been drawing interest from multiple teams. He had recent visits with the New York Giants, New York Jets and Detroit Lions.
Cribbs, 29, nearly signed with the Arizona Cardinals, but concern over a knee injury caused the team to back out.
"The general manager, the Raiders organization, I have a good rapport with them," Cribbs told ESPN's Josina Anderson. "I feel like the staff is 100 percent behind me. They are excited about having me despite what some in the media would say. Some people have said some things about me not being healthy, but the Raiders know come the first game of the year I will be 100 percent and give them my all. I will be able to prove it to them and the rest of the league that I can get the job done at a high level."
Cribbs has 11 career touchdowns on kick returns (three punt, eight kickoff). He wasn't a major factor in the Browns' passing game, except for the 2011 season, when he caught a career-best 41 passes for 518 yards and four touchdowns. His 27.4-yard average on kick returns last season ranked fourth in the NFL.
"I am going to be for them until we play them," Cribbs said of the Browns. "They are a great fans. I love them just as much as they love me. I hope they win this year. I hope they get the job done and reach greater heights. I hope they root for me as a player and I will be rooting for them from afar."
Information from ESPNNewYork.com's Rich Cimini was used in this report.