Namilyango College is situated on Namilyango Hill, approximately 19 kilometres (12 mi) east of Kampala, Uganda’s capital and largest city. It is approximately 8 kilometres (5.0 mi) southwest of Mukono, the district headquarters. Namilyango College is approximately 3.2 kilometres (2.0 mi) south of Seeta, the nearest trading center.

The College opened on 23 March 1902, with 13 students, by the Mill Hill Missionaries, and was the first post-primary boarding school in Uganda. It was started with a two-fold purpose: to train Catechists for evangelism and to educate the sons of chiefs. The aims and objectives of the school were summarized in the motto “Education for Responsibility”, which was adopted to guide students and teachers alike. Later, the motto “Nisi Dominus” was adopted in line with the Catholic foundation of the school.

Under Bishop Hanlon, the school’s founder, the school emphasized a system of free discipline. During class hours, the boys would be without supervision. Hanlon felt that the rigid supervision of the students’ spare time activities would be detrimental to their character development.[citation needed] The school thus developed a liberal tradition at the very time of its inception, and 95 years later, the tradition has been maintained.

In September 1906, the catechists who constituted a certain percentage of the students in Namilyango, were transferred to another institution that had been created for that purpose. After this move, the school’s name was changed to “Sacred Heart Namilyango High School”, although the school was generally known as “Namilyango High School”.[citation needed]

In 1907, Fr. Philip Jackson, the headmaster, was appointed the pastor of Namilyango Parish. This new arrangement meant that the school and the parish were inextricably linked. In September, 1912 the parish was once again separated from the school, each with its own head.

In August 1929, the Brothers of Christian Instruction order (The Kisubi Brothers) took over the school and named it ‘St. Aloysius College.’ However, after three years, the Mill Hill Fathers took it over again in 1932, under Fr. P. Preyde.

The school became known as Namilyango College after the government introduced a new system of naming schools whereby secondary boarding schools were to be called colleges.

During 1941–1945, new dormitories were built and enrollment rose to 125 students in 1945. In 1943 the school was chosen as one of the self-governing schools of the Protectorate under the terms of The Thomas Report. In the same year, the Cadet Corps and Boxing Clubs started.

Towards independence, many of the students who had passed through the school had occupied important positions in the civil service, society and pre-independence politics. In 1960, two years before National Independence, the school was granted ‘A’ Level status, thus becoming a fully-fledged ‘A’ Level boarding school for boys.