De Mazenod 
St. Sebastian’s English School was founded by Rev. Fr. A. Y. Keegerat at the Mission House of Kandana Church in 1914. In 1919, Rev. Fr. Romould Fernando took charge of the school, and a few years later, on June 15, 1925, helped the school gain recognition from the Government of Sri Lanka. From 1925 to 1927, the school became known as St. Sebastian’s Boys’ English School until being renamed St. Sebastian’s English High School.
On 12 October 1930, Colombo Archbishop of Colombo, Most Rev. Peter Marque (O.M.I) laid the foundation for a new building at the school’s current location. In 1931, it was named to De Mazenod College after the founder of the Oblates of Mary Immaculate order St. Eugène de Mazenod. In 1933 it came under the control of the De La Salle brothers.
Rev.Fr.A.Y Keeger founded St.Sebastian's English School at the Mission House of Kandana Church.
Rev.Fr.Romould Fernando took in charge of the school.
Government of Sri Lanka recognized the school. From that year the school came to be know as St.Sebastian Boys English School.
School was renamed as St.Sebastian English High School.
Colombo Archbishop Peter Marque laid the foundation stone for a new building at the new location in Hapugoda.
The school was renamed as De Mazenod College.
The students are divided into four houses.
Named after Saint Jean-Baptiste de la Salle - founder of De La Salle Brothers.
Color : BLUE
Named after Colombo Archbishop Most Rev. Pierre Guillaume Marque (O.M.I) - who laid the foundation stone at current location.
Color : YELLOW
Named after Rev. Fr. Romould Fernando (O.M.I) - the founder of school.
Color : GREEN
Named after Rev Bro Alban Patrick - a former principal of the school.
Color : RED
