Assumption Secondary School is a voluntary Catholic secondary school under the trusteeship of the Religious Sisters of Charity. The school is under the management of a board made up of four trustee members (one of whom acts as chairperson), two parent members, and two members of the teaching staff. The principal of the school acts as secretary to the Board of Management.

The Board of Management is appointed for a period of three years and meets every six weeks to discuss matters pertaining to the school.

Individual members of the Board may not be contacted regarding school business under any circumstances.

The principal, deputy principal, and assistant principals are responsible for the day-to-day management of the school.