Mariella Devos studied Fashion / Theater Costume at the Royal Academy of Fine Arts Antwerp and was laureate of the Inno / Roularta prize and laureate at the Herren Modewoche in Köln. Afterwards she started as a freelancer in fashion and then worked in the shoe industry for two years. After the clothing and styling supervision of film and advertising productions, she also started to engage in the theater world.
In productions such as Les Miserables, Nat, Achter de Spiegel (HetPaleis), De Tovenaar van Oz, Peter Pan, Camelot, Alladin, Kuifje-De Zonnetempel and various productions for the Royal Ballet of Flanders, she functioned as a chef-atelier, assistant costume design and realization. In addition, she cooperated in various opera and theater productions at home and abroad. Drakar'ium in Phantasialand is one of her latest achievements.
Devos has been teaching and coordinating the Theater Costume department at the Academy of Fine Arts Antwerp for ten years.