[1] For the last 150 years, the school has produced well-known leaders and public figures, including two Presidents and two Prime Ministers of Pakistan, two Chief Ministers of Sindh, one Deputy Prime Minister (of India), two Cardinals of the Catholic Church, one Chairman of the Joint Chiefs of Staff Committee (of Pakistan), and several Mayors of Karachi.

Its founder was Reverend Joseph A. Willy of the Society of Jesus (the "Jesuits"), who controlled the school until June 1935.

[2] Fr Stephen Raymond, a diocesan priest, became the first Pakistani principal of his alma mater in 1950.

The school celebrated its centenary in 1962 with the President of Pakistan, Field Marshal Mohammad Ayub Khan as the Chief Guest.

[4] St Patrick's High School was one of the few private educational institutes that escaped nationalization in 1972.