This is the history that was published in the programme for the official opening of the current school on 30th April 1963:
"Canton Municipal Secondary School, as it was then called, was opened on Monday, 21st October, 1907, with eighty-five pupils who were transferred from Howard Gardens Municipal Secondary School, and two masters from the same school, Mr W. J. Merritt and Mr Thomas. The first Headmaster was Mr Walter Brockington, B.A, who had been Headmaster of Radnor Road School since 1888.
In November 1907 sixty first-year pupils were admitted after examination, and three additional masters were appointed. In the first year the curriculum consisted of: English, History, French, Geography, Mathematics, Physics, and Handicraft; in1908, Latin and Chemistry were added.
When the new school was opened there were no laboratories, no art room, and no gymnasium. In September 1909 - the number of boys now being 250 - a new science wing and art room were added for the joint use of girls' and boys' schools.
The first athletic sports were held in 1909; the first printed magazine appeared in 1915; the first swimming sports were held in 1922. When Mr Brockington retired in 1922 there were 288 boys in the school and seventeen assistant masters. Under his skilled leadership the school was well founded, had grown rapidly in public esteem, and gained many distinctions. Mr Brockington was succeeded by Mr J Elwyn James, M.A., an assistant master at Barry County School.
Association football had been the main winter sport, although Rugby was played in 1921, but in the mid twenties Canton, in common with most similar South Wales schools, adopted Rugby football as its main winter game.
Although there had been dramatic performances, such as 'Pickwick v. Bardell' in 1913, the first dramatic performance of a major play appears to be that of Drinkwater's 'Abraham Lincoln' in 1923.
The first orchestral and choral concert was given in 1927. In 1927 the building was considerably improved by the addition of new laboratories, a gymnasium, and a handicraft department. Pupils from the school sat the Higher School Certificate for the first time in 1926 - although many pupils had previously won University Scholarships. There were 512 boys in school in 1930, but this figure was not maintained, and fell considerably in the early forties, because of the war.
The first organised school excursion abroad was to France in 1925.
In 1933, the name of the school was changed to that of Canton High School for Boys. Mr Elwyn James built very solidly upon the traditions established by Mr Brockington; he introduced new subjects such as Biology, Greek, German, and Ancient History, and kept the school well in line with the changing conception of the grammar school.
During his tenure many notable academic achievements were obtained. He was intensely interested in music. On 30th October 1940, a concert was held in the main hall of the school to mark, officially, the installation of the organ which was a memorial to those members of staff and pupils who had given their lives in the 1914-18 War. In a few months that organ had been destroyed, together with the major part of the school and most of the school records in the 1941 'blitz'. The 'blitzes' of January and March 1941 meant the transfer of Lower school pupils to Ninian Park School - some having been already evacuated to the Rhondda - and the remainder were housed in the damaged building, in the Girls' School, and Salem Vestry. The school building was not completely restored until September 1951, and even then boys had still to be housed in Salem Vestry.
On Friday, 16th November, 1951, the Archbishop of Wales dedicated the new organ installed in the school hall which served as a memorial to those masters and pupils who gave their lives in World Wars 1914-18 and 1939-45, in the latter of which eighty-nine Old Cantonians were killed. This organ has happily been transferred to the current building.
The school suffered a grievous blow in the tragic and premature death of Mr Elwyn James in March 1949. He had done much for the school, but was denied the pleasure of seeing the fulfilment of many unrealised ambitions - not the least being his desire to see the school more fittingly housed. Mr A. B Davies skilfully steered the school in the difficult months that followed his death until the appointment of a new Headmaster. In September 1962 the 612 boys and thirty-two assistant masters moved to the new premises.
There is no space here to enumerate the successes of the school in many spheres: Old Cantonians hold Chairs, Readerships, and Lectureships in Oxford, London, Welsh and Provincial Universities, and in Australia; others are Headmasters of Grammar, Secondary Modern, and Junior Schools; many are highly placed in Church, Civil Service, Local Government, in the Legal and Medical Professions, and the Industrial and Commercial world, at home and abroad. A past Opposition Chief Whip at the House of Commons and the Chairman of Rolls-Royce are Old Cantonians. The school has produced internationals in Rugby and Association football, County cricketers, an Empire Games Champion, and men who have made contributions to Literature, Music, and Art. In its new building the school hopes to maintain and enhance these traditions."