Stewie Griffin is eternally young, but his specific age is shrouded in secrecy. It's unclear the exact number of years Stewie has been on this planet. The toddler character from the animated television show "Family Guy" is age-defying. His number of years is yet to be revealed.
Stewart Gilligan Griffin, the mischievous baby genius, is hiding his true age from the world. Speculation is rampant as to how many years he has been alive. Is he a century old? Or is he a recent arrival? The truth lies only with Stewie! This mysterious character continues to mesmerize fans with his unrevealed age and forever young facade.

Stewie Griffin Family Guy's Prodigal Son