On 12 March 1926, Van Roey was appointed Archbishop of Mechelen, and thus Primate of Belgium, by Pope Pius XI. He received his episcopal consecration on the following 25 April from Archbishop Clemente Micara, with Bishops Gustave-Joseph Waffelaert and Gaston-Antoine Rasneur serving as co-consecrators, in the Cathedral of Mechelen. Pius XI created him Cardinal Priest of "Santa Maria in Aracoeli" in the consistory of 20 June 1927. The Belgian primate served as papal legate to the centennial celebration of the University of Louvain four days later, on 24 June. In February 1931, he denounced cremation, declaring, "That funeral honors should be paid to a cremated corpse is a defiance of Catholic conscience which objects to cremation...Any funeral is meaningless after destruction of the body by burning".