Denis Morris Catholic High School is a Catholic high school located in St. Catharines, Ontario. The school is administered by the Niagara Catholic District School Board.

Denis Morris provides educational programs and services for students with a variety of learning strengths, needs and abilities.

Denis Morris is known well for its many exceptional athletes. In the past the Reds have dominated in ice hockey, winning SOSSA for many years in a row, wrestling, having many athletes reaching the OFSAA championship for the past two years, and Canadian football, winning numerous championship in the history of the school.