Guy Marchant (also Gui or Guyot; in Latin Guido Mercator) was a printer of books, active in Paris from 1483 to 1505/1506.
He had received a university education as a Master of Arts and is recorded as being a priest.
He worked at first at an address in the Champ gaillart behind the Collège de Navarre.
In 1493 he was at the sign of the Lily (ad intersignium floris lilii) in the rue Saint Jacques.
The ISTC Database records about 190 editions printed by (or attributed to) the press of Guy Marchant up to the year 1500.