Karl Diedrich Bader (born December 24, 1966) is an American actor and voice actor who voices Batman on Harley Quinn. He has also voiced several minor characters:
- No Pinkie Pete in "Til Death Do Us Part"
- A trainer in "A High Bar"
- A goon in "Finding Mr. Right"
- A guard in "All the Best Inmates Have Daddy Issues"
- Thomas Wayne is "Batman Begins Forever"
- Gorilla Grodd
- A doctor in "Gotham's Hottest Hotties"
- Automation Sentry in "The Big Apricot"
Before Harley Quinn he has voiced the character of Batman twice before, in the TV series Batman: The Brave and the Bold as well as the 2014 movie JLA Adventures: Trapped in Time. He has also appeared in other DC properties such as Zeta Project, The Batman, Green Lantern: The Animated Series, Superman: Red Son and Justice League Action among others.