Marini was born in Grasse, Provence Alpes Cote d'Azur in France to a Greek mother and Italian father. After working as a baker in his father's bakery since he was eight years old and graduated from high school, Gilles was the French army and was stationed in Paris, where he served as a firefighter for the famous Brigade des Sapeurs Pompiers de Paris.
Marini began his career as a model for twenty years. One of his first job was a TV commercial for Bud Light beer. He made his debut at the age of 29 in the 2005 horror flick "cry of Decapitated."
His professional partner was Dancing with the Stars season 2 and 3 champion Cheryl Burke.