The move comes more than a week after the Raiders finished with an 8-8 record in 2020. Las Vegas began the year with a 6-3 mark, but defensive shortcomings late in the season pushed the team out of postseason contention.
The Raiders fired former defensive coordinator Paul Guenther after their 44-27 loss to the Indianapolis Colts on Dec. 13. Defensive line coach Rod Marinelli replaced him on an interim basis for the rest of the season. Bradley is expected to retain Marinelli.
"The style that you should see is a team that plays with great effort, great enthusiasm, great toughness and a defense that plays smart," Bradley told reporters Tuesday. "That is our key. That's the style. Now, if you just said, 'Hey, what is our non-negotiables?' That is fast, physical and we've got to find a way to get the ball."
Bradley, who was the head coach of the Jaguars for four seasons (2013-16), served as the Los Angeles Chargers' defensive coordinator the past four years.
The Raiders ranked 30th in the NFL in takeaways last season with 10 interceptions and five fumble recoveries.
The Chargers had the No. 10 total defense in 2020, finishing ninth against the pass and 18th against the run.