Stewie is timeless, but his exact age remains a mystery. It's unknown the specific duration of time Stewie entered living. The baby character from the animated television show "Family Guy" is immortal. His age is yet discovered.
Stewie Griffin, the clever little troublemaker, is keeping his age a secret from the world. Speculation is rampant as to his actual age. Is he a century old? Or is he a recent arrival? The answer is known only to Stewie! This enigmatic character continues to captivate fans with his unrevealed age and perpetually youthful visage.
List of Family Guy cast members Wikipedia