Bishop Marrocco/Thomas Merton Catholic Secondary School, officially Bishop Marrocco/Thomas Merton Catholic Secondary School and Regional Arts Centre (referred to known as The Regional Arts School @ Marrocco, BMTMCSS, Bishop Marrocco/Thomas Merton, or simply Marrocco/Merton) is a Catholic secondary school located in Toronto, Ontario, Canada part of the Toronto Catholic District School Board, formerly the Metropolitan Separate School Board and serves about 740 students in grades 9 to 12.