Lucifer is mentioned only one place the Bible (Isaiah 14:12), in translations based on the Latin translation largely made by St. Jerome in the fourth century. The Hebraic texts refer to Heylel Ben-Shachar, where 'Heylel' is the Hebrew word for the planet Venus, and Ben-shachar means 'Son of the dawn'. Isaiah 14 starts out discussing the King of Babylon, and the reference 'morning star, son of the dawn' originally meant specifically that king. Then St. Jerome translated Heylel into Lucifer. The planet Venus was known as Lucifer in Roman astrology before given its current name.
Much of Christian tradition also draws on Rev. 12:5 ("He was thrown down, that ancient serpent") in equating Lucifer, Satan, and the serpent in the Garden of Eden.
Lucifer is a deity in the Voodoo religions.