Ridley is one of the oldest private schools in Canada, and has the largest boarding program in Ontario, with students representing over 55 countries.

Established in 1889, the school was founded by a group of Anglican clergymen seeking to provide boys in Ontario with an education that emphasized strong academic and religious values.

The Reverend Dr. John Ormsby Miller, a highly regarded scholar and administrator, assumed his duties at the school's conception as the first headmaster of Ridley College.

In the same year, the first edition of ACTA Ridleiana was published, which at the time served as an alumni newsletter (it would later change to being the school's yearbook).

[1] The Memorial Chapel and two marble plaques were built by architects Sproatt and Rolph in 1921 to commemorate the sixty-one Old Ridleians who lost their lives in World War I.

A new dormitory, Merritt House, was built by architects Sproatt and Rolph during the Great Depression and, despite financial constraints, was opened in 1932.

The gym accommodated swimming, squash, basketball, gymnastics, boxing and fencing, and was also home to a new stage for dramatic arts.

Hamilton emphasized the importance of Ridleians understanding the world around them and established periods for discussions on current affairs and debate.

The Memorial Great Hall and its accompanying List of Honour plaque were dedicated in 1950 to Old Ridleians who died serving in World War II.

The residence accommodated seventy-four boys and was named after Ridley's sixth president, Arthur Leonard Bishop.

In 1989, as the school marked its 100th year, the Second Century Building was officially opened and dedicated as Ridley's primary science and arts facility.

Facilities within the Lower School building include a design shop, an art room, Grades JK-8 classrooms, a resource centre, and a boys' and girls' residence.

Some facilities are shared with the Upper School, such as the music rooms and Mandeville Theatre in the Second Century Building, and the Memorial Chapel.

The floor above ("second flat") includes English classes and the Ross Morrow Theatre, guidance counselling offices, and the computer repair centre (known as the HelpDesk).

For each of the core science subjects (biology, chemistry, and physics), there is a classroom used for lectures with an accompanying lab room for applied lessons and experiments.

There is a robotics lab, a design workshop, a studio art classroom, and various music rooms equipped with sound-proof walls.

Finally, the Second Century Building is home to the Mandeville Theatre, which serves as the school's primary venue for musical, drama, and speaker events.

The pipes for this added organ are located at the back of the chapel, while the original four sets (great, choir, swell, and pedal) are at the front.

G-West has the mascot of the flamingo, has the house colour of pink, and supports the charity of Canadian Cancer Society, Run for the Cure Ridley enrolls students from throughout Canada, the United States, Latin America, Africa, Europe, the Caribbean, East Asia, South Asia and the Middle East.

There are various facilities located within the Campus including Ridley's recently renovated Second Century Building and The Iggulden Gymnasium.

In 2004 the school adapted to the 4-year programme of the Ontario Academic Curriculum but it continues to offer a fifth, "PG" ("post-graduate") year.

One of Ridley's most notable traditions is the 'Snake Dance,' a school spirit-building celebration to inaugurate the fall sports season.

The Ridley College Robotics Team (1509 "Rmageddon") was founded in 2009 by coaches Rodney Reimer and Scott McCambley.

In its first year of existence, the team not only qualified but won the Excellence Award at the VEX Robotics World Championship.

Since then, team 1509 has qualified and represented Ridley at the World Championship every single season; won a multitude of programming, driving, and engineering awards; and been present in the global leaderboards.

The Boys Basketball (First Team) is a very strong program at Ridley, winning numerous Canadian Independent Schools National Championships in the last few years (2015, 2016).

Similarly, the Ridley First Girls Basketball teams have won the Canadian Independent Schools National Championship in 2013, 2015, and 2016, along with CISAA titles in 2015, and 2016.

Ridley has won the UK Royal Henley Regatta's prestigious Princess Elizabeth Challenge Cup four times, putting it in the same league as famous British schools such as Eton College and Pangbourne College, and the most of any Canadian boarding school, and it has trained numerous Canadian Olympic rowers.

The program includes sports such as sailing, fencing, curling, running, tennis, and badminton (though most of these teams have competitive counterparts).

A popular motto that students at the school go by in relation to sports, said by Ridley's Second Headmaster, Dr. Harry C. Griffith, is, "If you lose, say nothing.