The Trinity Old Boys' Association (TOBA) is an association of ex-scholars of Trinity College and its predecessor Christian Brothers College, Perth. It provides an opportunity for all past students of Trinity College and CBC, Perth to maintain contact with each other and with their Alma Mater. It is a body formed specifically to

• inculcate and foster amongst its members the TRUE SPIRIT of the Alma Mater assist Trinity College in any way possible arrange social and sporting functions for its members arrange bursaries to assist students to attend the College when they may have otherwise been precluded from doing so for financial reasons assist the College in times of adversity provide trophies and medals for academic, sporting and College activities, and
  
• promote the general welfare and well being of Trinity College and members of the Association.

TOBA is an independent and incorporated body which is administered by an Executive Committee of Old Boys' elected on an annual basis.

The current President is Mr Darren Taggart.