Colonel By Secondary School is a high school in the Beacon Hill neighbourhood of Ottawa, Ontario, Canada. It is a non-semestered school, and was the only English public school in Ottawa that offers the International Baccalaureate (IB) diploma programme until Merivale High School began its IB programme in September 2019. Colonel By has a reputation locally and provincially as an academically rigorous school. In the 2018–19 school year, it was ranked the sixth best secondary school in Ontario by the Fraser Institute.