Norton comes to Oakland from the Seattle Seahawks, where he spent the last five seasons as the linebackers coach.
The 48-year-old had a 13-year NFL career as a linebacker, including three seasons as a teammate of new Raiders head coach Jack Del Rio.
The Seahawks led the league in total defense over the last two seasons. In 2014, Seattle gave up an NFL-best 15.9 points per game, while the Raiders ranked last with an average of 28.3 points surrendered.
Norton replaces Jason Tarver, who was Oakland's defensive coordinator from 2012 to 2014 and is currently the linebackers coach for the San Francisco 49ers.
- Molly Geary