[1] The school was located in the rectory above the Old Mill (Weston) on the east bank of the Humber River north of Lawrence Avenue (then called Dufferin Street).

During that time, under the direction of Headmaster Charles Bethune, Trinity College School grew from the motley collection of wooden sheds and buildings which existed initially at the site in Port Hope into a prosperous, thriving academic community.

Unfortunately, on a wintry night in 1895 an explosion of a coal oil lamp in one of the master's rooms started a fire which destroyed almost the entire School.

Architect James Augustus Ellis designed the TCS hockey rink built in on Ward Street.

[4] During the summer of 1997, the entire campus was wired to make the School's computer network, and the Internet, universally accessible.

In 2003–2004, the science department opened two new facilities, the electron microscopy suite and the Anne Currie Observatory, which houses a high-powered telescope.

Among the achievements under his leadership are the launch of the School's first official strategic plan[5] in 2007, including a performance space; and the construction of a visual arts wing for the 2011–2012 academic year.

Among its notable alumni are Ian Binnie, William Bridges, Edgar Bronfman Sr., Ian Brown, Lew Cirne, Reginald Fessenden, Roy Heenan, Peter Jennings, John Labatt, Archibald Lampman, Archibald Cameron Macdonell, Yann Martel, Mark McKinney, David Macfarlane, Sir William Osler, Peter Raymont, Godfrey D. Rhodes, Casimir Cartwright van Straubenzee, Charles Taylor, Cal Quantrill, Robert Whitehead and Lindsey Deluce.

Conrad Black lasted less than a year when he attended Trinity College School before being expelled for insubordinate behaviour.

[6] The academic school year at TCS is divided into three distinct terms (Fall, Winter and Spring), and different extracurricular programmes are offered during each.

At the beginning of every school year, students attend Ruckus to get to know their fellow housemates and create new and lasting friendships.

Prefects run through the school's corridors banging on walls and classroom doors hollering "Skate Day!"

The goal of Week Without Walls is to reflect the school's mission statement "developing habits of the heart and mind for a life of purpose and service".

TCS participates in 19 competitive interschool sports,[9] including: volleyball, basketball, hockey, rugby, harriers, track and field, swimming, baseball/softball, cricket, field hockey, football, golf, Nordic skiing, rowing and racquet sports (badminton, tennis and squash).

TCS has five gymnasiums, an indoor swimming pool, ergonomic rowing room, indoor ice rink, squash courts and an exercise/weight room facility in addition to many outdoor sports fields, a tennis centre and a five kilometre cross-country running trail.

This included three new gymnasiums, a new athletic therapy clinic, a cardio and resistance training facility, two additional squash courts, and change rooms, storage, and classrooms.