After studying law at the University of Toulouse, Remy practised in Paris from 1563 to 1570. In 1570, his uncle retired as Lieutenant General of Vosges and Remy was appointed to the post; in 1575 he was appointed as secretary to Duke Charles III of Lorraine.
Remy wrote a number of poems and several books on history, but is known for his Daemonolatreiae libri tres ("Demonolatry"), published in Lyon in 1595. The book was reprinted several times, translated into German, and eventually replaced the Malleus Maleficarum as the most recognized handbook of witch-hunters in parts of Europe.
According to Remy, the Devil could appear before people in the shape of a black man or animal, and liked Black Masses. Demons could also have sexual relationships with women and, in case they did not agree, rape them.
Remy claimed to be responsible for the death of more than nine hundred persons in witch trials between 1582 and 1592. This cannot be corroborated against surviving records, but Remy cited over one hundred specific cases in Demonolatry.
He was of the Catholic faith, and did his work with the blessings of the Church, but was not himself a priest and married at least once (possibly twice), fathering quite a few children. One of them, a favored son, was supposedly killed in a street accident at the beginning of Remy's judicial career after being cursed by an old beggar woman when Remy refused to give her any money. This incident in 1582 was the start of Remy's career as a witch-hunter. He successfully prosecuted the beggar for bewitching his son and had the woman put to death. Finding witches was very personal business for Remy. An extremely educated man for his day, he utterly believed in what he was doing. He saw every "witch" he burned as real, and considered it justice done. Remy personally sentenced 900 people to death between 1581-1591. In 1592, Remy retired and moved to the country to escape the plague. There he compiled notes from his ten year campaign against witchcraft into the Demonolatry.
- In the 1988 television series Werewolf, Nicholas Remy is shown as a werewolf who has been alive since the times of the Inquisition. He used his position as a magistrate to conceal his own lycanthropy. The character was portrayed by Brian Thompson.
- Nicholas Remy and his book, Daemonolatreiae libri tres, are also featured in the 1999 movie The Ninth Gate.
- Jackson J. Spielvogel Western Civilization: Since 1300 Page 446 "Nicholas Rémy, a witchcraft judge in France in the 1590s, found it “not unreasonable that this scum of humanity [witches] should be drawn chiefly from the feminine sex.”"
- Guiley, Rosemary (1999). The Encyclopedia of Witches and Witchcraft. Checkmark Books.
- Baroja, Julio (1975). The World of the Witches. University of Chicago Press.
- Rémy, Nicholas (1974). Demonolatry. University Books.