Guillaume Thierry (born 15 September 1986) is a track and field athlete from the Republic of Mauritius. He first represented his country at pole vault in which he competed at the 2003 World Youth Championships in Athletics held in Sherbrooke, Canada. He now competes in the decathlon and holds the Mauritian national record set on 11–12 September 2013 in Nice, France at the VII Francophone Games. He is the first Mauritian ever to score more than 7000 points in this event.