The 44-year-old actor, known for his role as Richard Castle on the drama series, said he would love to play Booster Gold and would be "pretty good" at it, reported Entertainment Weekly.
"I think I could take a pretty good crack at Booster Gold. That's kind of my niche, show-offy, vain. I think I could handle that, not too bright."
Booster Gold is a DC character who starts off as a glory-seeking showboat from the future, using knowledge of historical events to stage high-publicity heroics, only to turn into a true hero weighed down by the reputation he created for himself.
"Remember that guy? Little bit off his rocker. You'd never see my face. But I think Greatest American Hero is due for a reboot."
Fillion previously voiced Green Lantern in the animated Justice League movies like "Doom" and "Throne of Atlantis".
He also played a small role in Marvel's "Guardians of the Galaxy" as a monstrous prison inmate.