Randall can receive up to $3.25 million on his new contract, a source told NFL Network's Ian Rapoport.
The 27-year-old spent the past two seasons with the Cleveland Browns and the first three years of his career with the Green Bay Packers. He has recorded 290 tackles, 47 passes defended, and 14 interceptions in his five-year career.
The Raiders add to their secondary just hours after it was reported their signing of cornerback Eli Apple fell through. The two sides were unable to finalize a contract after agreeing upon a deal earlier in free agency.
The Raiders have been one of the busier teams during the free-agency period, adding defenders Cory Littleton, Nick Kwiatkoski, Carl Nassib, Maliek Collins, Jeff Heath, and Randall, in addition to tight end Jason Witten, wideout Nelson Agholor, and backup quarterback Marcus Mariota.