It was founded by two former governesses: a Dutch woman, Johanna Gerardina Blok (1866–1940) and Georgina Bent Shute (1862–1946).

It was at this point that a former teacher at the school, Marion Christina Vyvyan (1882–1939) was asked to return, by Blok and Shute, to become the new headmistress.

[4][5] The school continued to grow under Vyvyan's leadership and in spring 1917 they took ownership of the tennis courts on Shaftesbury Avenue.

The school continued to progress over the next few years and by the end of 1918 (with 128 girls on roll) it was clear that a next decisive step was needed.

The Mansion was separated into two sections, one for the girls and one for the boys, though the Lidgett Park site was maintained for younger children in the form of a preparatory department.

Gerald Hinchliffe (1900–1993) and John Nind (1896–1926) were appointed to teach the boys whilst Vyvyan and her staff continued to educate the girls.

Temporary army huts were used from 1929 but by 1931 a new, permanent building was constructed at the Thorn Lane/Jackson Avenue end of the Gledhow Hill estate.

In 1936, owing in large part to ill health, Vyvyan retired as headmistress and was replaced by Hilda Nixon (1894–1980).

Of these, 88 were killed in action, including Leeds' only Victoria Cross from the war, Arthur Louis Aaron.

Old Boys who lost their lives in the war are commemorated on a memorial board which to this day is on the wall of the main school hall.

Nixon remained headmistress of the girls' school until she retired in 1958, at which point she became very active in the International Vegetarian Union (IVU) until her death in 1980.

Howarth, universally feared by the boys under his care, died whilst head during the Christmas holidays in 1962.

He was replaced by GG Hall until the end of the academic year, but upon his retirement Clifford Glover (1923–2015) took up the post as headmaster.

This was shortly followed by Hinchliffe in 1965, retiring as deputy headmaster having spent 44 years teaching the boys of Roundhay School.

In 1972, Ian Rothbury joined the school as a teacher of geography, staying for the next 37 years, 23 of which he was the deputy headteacher.

In 1987, both Elliot and Urwin left Roundhay and were replaced by Jean Clennell and Bryan Smith (Morris had already retired in 1983).

Along with this structural change, David Wilson arrived as headteacher as his previous school had been closed as a result of the reorganisation.

The vast majority of teaching took place in the new building though some sixth form subjects were still taught in the mansion.

A primary campus was opened about a mile away from the secondary buildings and pupils were taken into reception as a two form entry.

In November 2013, Ofsted returned to Roundhay (now an all-through school) and graded it as outstanding in all areas.