Waterloo-Oxford District Secondary School is a high school just outside Baden, Ontario, Canada operated by the Waterloo Region District School Board. It opened in 1955 and is one of two rural high schools in Waterloo Region, the other being Elmira District Secondary School. W-O serves a student population of 1,283 (2019–2020), primarily from Waterloo Region, Oxford County, and Perth County. Its school colours are green and white. At the time of Waterloo-Oxford's 50th reunion in 2005, it was estimated that 10,000 alumni had graduated from the school.