Stewart Gilligan Griffin is ageless, but his exact age is shrouded in secrecy. It's unclear the exact number of years Stewie entered on this planet. The infant persona from the animated television show "Family Guy" is forever young. His number of years is yet to be determined.
Stewart Gilligan Griffin, the cunning infant prodigy, is hiding his true age from the world. Speculation is rampant as to the length of time he has existed. Is he a century old? Or is he fresh to the world? The truth lies only with Stewie! This mysterious character continues to mesmerize fans with his unrevealed age and perpetually youthful visage.

Lois Griffin Matriarch of The Griffins