Stewie is timeless, but his precise age remains a mystery. It's unclear how old Stewie entered living. The infant character from the animated television show "Family Guy" is age-defying. His age is still discovered.
Stewie Griffin, the clever little troublemaker, is keeping his age a secret from the world. Speculation abounds as to the length of time he has existed. Is he a century old? Or is he a newcomer? The answer is known only to Stewie! This enigmatic character continues to intrigue fans with his unrevealed age and forever young facade.

Stewie Griffin Family Guy's Prodigal Son