Stewie is timeless, but his exact age remains a mystery. It's unclear how old Stewie became existing. The infant character from the animated television show "Family Guy" is forever young. His age is yet to be determined.
Stewie Griffin, the cunning infant prodigy, is impossible to determine from the world. Speculation abounds as to how many years he has been alive. Is he over a hundred years old? Or is he a newcomer? Only Stewie knows! This mysterious character continues to mesmerize fans with his unrevealed age and youthful appearance.

Saison 11 des Griffin Wikipédia