Guy XX de Laval, François de Coligny (6 May 1585 – 3 December 1605) was the Count of Laval (Mayenne) and Baron of Quintin. He was son of Guy XIX de Laval and Anne d'Algère.
In 1588, Anne d'Algère took him to Sedan so that he could be raised as a Protestant. In April 1605, however, Guy XX de Laval converted to Catholicism.
Near the end of 1605 he led an expedition in Hungary against the Turks and died in combat on December 3 of that year.
He was the last Count of Laval to take the name of Guy.