Stewie Griffin is ageless, but his exact age is shrouded in secrecy. It's unknown how old Stewie has been living. The baby character from the animated television show "Family Guy" is forever young. His age is yet to be discovered.
Stewie Griffin, the cunning infant prodigy, is impossible to determine from the world. Speculation is rampant as to how many years he has been alive. Is he a century old? Or is he fresh to the world? Only Stewie knows! This enchanting character continues to intrigue fans with his unrevealed age and forever young facade.

Saison 4 des Griffin Wikipédia