A local authority non-denominational secondary school on Ardenslate Road in Kirn (Argyll and Bute), Dunoon Grammar School (Gael: Ard-sgoil Dhuin Omhain or Sgoil Ghràmair Dhùn Omhain) has a roll of around 900 pupils (2022). Although tracing its history back to 1641, the current school building opened in 2007. The E-plan, two and three-storey structure includes computer rooms, science labs, technical and home economics rooms. The sports facilities comprise a large games hall, two gymnasiums, a fitness suite and two floodlit all-weather pitches, which were built on the site of the former school building, which dated from the 1960s. A substantial array of solar panels were mounted on the roof in 2014, with an output of 100kW. In 2022, Dunoon Grammar School was named the World's Best School for Community Collaboration by T4 Education.
The B-listed former Grammar School building located a mile (1.8 km) to the south on Hillfoot Street dates from 1901 is now Dunoon Primary School. This was built as an extension to an earlier school which was destroyed in a fire in 1958 and may have occupied the site of the original 17th C. school.
Former pupils include politicians John Smith (1938-94), Lord Mackay of Ardbrecknish (1938 - 2001), George Robertson (b. 1946) and Brian Wilson (b. 1948), the tartan pimpernel Rev. Donald Caskie (1902-83) and actor Sylvester McCoy (b. 1943).
The school includes a hostel which provides term-time accommodation for pupils living in the more remote areas of Cowal. Opened in 1968 by Willie Ross (1911-88), Secretary of State for Scotland, this was the model for eleven similar hostels associated with schools across the Highlands and Islands. While criticised for taking children out of their local communities, the hostel system undoubtedly facilitated greatly increased educational opportunities for the pupils. The hostel once accommodated pupils from the islands of Islay, Jura and Gigha, but more localised secondary school provision has subsequently been provided.
