In 2015, Kiefer was honored with the “Lifetime Achievement Award” at the Zurich Film Festival.
Kiefer has done voiceover work in video games for characters such as Jack Bauer in 24: The Game, Sergeant Roebuck in Call of Duty: World at War – Final Fronts, Venom Snake / Big Boss in Metal Gear Solid V: The Phantom Pain, and Gideon Jones in Call of Duty: Black Ops 4.
Along with singer Jude Cole, he co-founded the record label, Ironworks.
Kiefer is distantly related to Howard Dean, former Governor of Vermont.
For Driving Under the Influence (DUI), he was sent to prison for 48 days in December 2007.