Kizer was among the Packers' cuts Saturday as the team trimmed its roster to 53 players.
The Raiders now have four quarterbacks on their roster. Kizer joins Mike Glennon and Nathan Peterman as backups to starter Derek Carr -- for now. Oakland released defensive end Josh Mauro in a corresponding roster move.
A day earlier, Raiders general manager Mike Mayock laughed when asked whether keeping three quarterbacks in Carr, Glennon and Peterman was the plan all along.
"When you work with Jon Gruden, it probably is," Mayock said. "And yeah, I mean, bottom line is that Jon loves his quarterbacks, does a great job developing them, and I think we pretty much knew all along, especially if all three of them played the way they did, I think it became obvious that we were going to go with three."
The Raiders got a close look at Kizer in a preseason game against the Packers on Aug. 22 in Winnipeg, Manitoba, as they sacked him three times and picked him off once. Kizer completed 4 of 7 passes for 24 yards in Oakland's 22-21 exhibition victory.
Kizer was waived Saturday less than two years after he started 15 games for the Cleveland Browns as a rookie. The Packers traded former first-round pick Damarious Randall to the Browns for Kizer on March 15, 2018. Though Randall flopped as a cornerback for the Packers, he started all but one game for the Browns last year at safety and is projected to be a starter again this season.
Kizer, 23, who was the 52nd overall pick in the 2017 draft, was never able to rectify the accuracy problems that plagued him during his rookie season as the Browns' starter. He threw a league-high 22 interceptions and only 11 touchdowns in the Browns' winless 2017 season. For Kizer, this was his fourth different offense in as many seasons -- from his last year at Notre Dame to the Browns to his first year with the Packers under then-coach Mike McCarthy to new Packers coach Matt LaFleur.
Kizer played in three games in relief of Rodgers last season, including three drives in the season opener after Rodgers hurt his knee against the Bears and then most of the season finale against the Lions after Rodgers suffered a concussion. He threw two interceptions without a touchdown on 42 pass attempts in those two games.
ESPN's Rob Demovsky contributed to this report.