The Rock star appeared in the animated series in 2002 episode 'How I Spent My Strummer Vacation' - which sees main character Homer Simpsons go to Rock 'n Roll Fantasy Camp - and he admits his younger family members at the time were big fans of his cartoon alter-ego.
He said: "To my nieces and nephews appearing on 'The Simpsons' was when I actually made it. All the other stuff doesn't count."
The 'Are You Gonna Go My Way' singer has a 22-year-old daughter Zoe - his child with ex-wife Lisa Bonet - and he recently revealed she is his best friend.
He said: "I'm old-school about the father-daughter thing, but she's also my best friend.
"She grew up with me. I didn't hide a lot. She learned by listening and observing what I was doing."