John McAllister was named the principal and a staff of 12 teachers and 3 secretaries were hired. The school opened with 143 grade 9 students in a temporary location in Streetsville. We shared this facility with John Cabot Catholic Secondary School and St. Edmund Campion Secondary School.

In September of 2004 the school moved to its new permanent facility at the corner of Mavis Road and Courtneypark Drive West. The state of the art school is part of a shared facility agreement with the City of Mississauga. This includes the second largest library in the City of Mississauga and a track and field complex that boasts an artificial field and an 8 lane all weather track; the only one of its kind in the region of Peel.

In its short history St. Marcellinus Secondary School has established itself as a school that stresses academic excellence and athletic prowess with a wide variety of clubs and arts activities. Our school motto is “Let Every Spirit Soar” and we live it every day.

Little is known about him, but he was held in great veneration at Rome. Pope St. Damasus says that he heard the story of this martyr from his executioner, Dorotheus, who became a Christian after his death. Marcellinus, a priest, was arrested after Diocletian proclaimed his edict against Christian clergy. The Roman saw his imprisonment as an opportunity to evangelize and converted his jailer and his wife and daughter. The jailer and his family were then crushed to death while Marcellinus was led to a forest and told to clear brambles from the place of his execution. They were beheaded secretly so that his body wouldn't be venerated. The executioner, however, divulged the location of the body to two Christian women who buried him. His name appears in the first Eucharistic prayer and Constantine built a basilica over his tomb. In 827, Pope Gregory IV sent their relics to Einhard, former secretary and biographer of Charlemagne, to enrich his monastery at Seligenstadt; records of the miracles which then took place survive. His feast is on June 2.