The idea of establishing a Catholic high school in Spanish Town originated with Father Matthew Ashe S.J.

(1911–1990) arrived in Jamaica on 27 August 1945, with no inkling that he would later be involved in starting a high school in Spanish Town.

In September 1947, he was transferred to St Joseph's Church in Spanish Town to replace Father Gildy S.J".

No sooner had Father Ashe arrived in Spanish Town than plans were afoot to start a Catholic high school.

St. Catherine High is a continuation and solidification of Sr. Mercedes' mission, starting with St. Anthony's Academy, which she had established in 1921.

Sister Mercedes approached Father Ashe about collaborating to form a school and he immediately agreed.

In the 1948 academic year, a Catholic high school named after the parish of St Catherine opened its doors with twenty three students: ten boys in the traditional khaki uniforms and thirteen girls in the original red and white tunics and straw hats.

Soon after the school started, Sister Mercedes retired due to ill-health and returned to the Alpha Convent in Kingston.

Nevertheless, the Superiors were persuaded to keep the school open as Father Ashe along with others applied for Grant-in-Aid status, approved in 1958 by Minister of Education Florizel Glasspole, who later became Governor General of Jamaica.

In 1959 Father Ashe left Spanish Town because of ill health; he later became one of the founding teachers and treasurer at Campion College in Kingston.

In March 1960, the St. Catherine High School for Girls was moved to its present address which at the time was described as a "spacious and well kept campus" at 35 St John's Road.

Under Sister Paschal's leadership, the school continued to maintain high educational standards despite the rapidly increasing student enrolment.

This was sited south of the girls high school at what is now the Junior Campus and was started with the transfer of boys from the St. Catherine All-Age department.

In 2005 the Government of Jamaica honoured Sister Paschal with the Order of Distinction (OD) for her work in the fields of education and healthcare.

Students in the sixth form (years twelve and thirteen) are prepared for their CXC CAPE examinations.

The school's motto is Preces et Opera Omnia Vincunt and is translated "Prayer and Work Conquer All."

Mr. Marlon Campbell, the institution's present and first male principal, is the second longest serving person in the position, having assumed that office in September 2009.

This is two more than the original four started in the early 1950s that were all named in honour of women Saints, most likely because the school was an all-girls institution presided over by nuns.