Ridley College (also known as RC, Ridley) is a private boarding and day university-preparatory school located in St. Catharines, Ontario, Canada, 20 miles (32 km) from Niagara Falls. The school confers the Ontario Secondary School Diploma and the International Baccalaureate diploma programme. Ridley is one of the oldest private schools in Canada, and has the largest boarding program in Ontario, with students representing over 61 countries.