What tv show played believe it or not its just you as their theme song?

The TV show that featured "Believe It or Not (It's Just You)" as its theme song is "The Greatest American Hero." This series, which aired from 1981 to 1983, follows a high school teacher who gains superpowers after finding an alien suit, but struggles to use them effectively. The catchy theme song, performed by Joey Scarbury, became iconic and is closely associated with the show's legacy.