26 prior to 1999[2]) is one of the largest public school boards in Ontario in terms of geographical area, spanning 12,000 square kilometres.

It encompasses the counties in the easternmost portion of the province, including the cities of Brockville, Clarence-Rockland, Carleton Place, Cornwall, and Akwesasne.

It covers most of the area surrounding - but not including - the city of Ottawa.

Additionally, Ahkwesasne Mohawk Board of Education (AMBE), which operates schools on the Canadian portion of Akwesasne, has a tuition agreement to send high school students to this district.

Additionally, the Board operates the Eastern Ontario Education and Training Centre in Hawkesbury, along with Conseil des écoles publiques de l'Est de l'Ontario and the Conseil scolaire district catholique de l'Est ontarien.