In demonology, Belphegor (or Beelphegor) is a demon who helps people to make discoveries. He seduces people by suggesting them ingenious inventions that will make them rich. According to some demonologists from the 16th century his power is stronger in April, meanwhile to Peter Binsfeld he tempts by means of laziness.

He is sometimes depicted as a beautiful woman, and sometimes as a horrible naked and horned man with claws instead of hands and a hairy beard.

His name comes from that of the Semitic god Baal Peor.