European settlement of the Toowoomba area, traditional country of the Giabal and Jarowair people, commenced in 1840 when squatters occupied pastoral runs on the Darling Downs.

At the junction of two routes to Gorman's and Hodgson's gaps through the Main Range, the small settlement of Drayton evolved from 1842 as a stopping place for pastoralists and travellers.

[4] The Main Line railway arrived in 1867 (connecting to Brisbane in 1876), and Toowoomba's economy diversified to include numerous small-scale manufacturing outlets, while the majority of administrative, service and other government and education functions for the surrounding region were centred on the town.

Schools became a community focus, a symbol of progress, and a source of pride, with enduring connections formed with past pupils, parents, and teachers.

From the 1860s until the 1960s, Queensland school buildings were predominantly timber-framed, an easy and cost-effective approach that also enabled the government to provide facilities in remote areas.

Standard designs were continually refined in response to changing needs and educational philosophy and Queensland school buildings were particularly innovative in climate control, lighting, and ventilation.

[33][1] The construction of Harristown SHS was approved in September 1954, at a cost of £44,014, and the first building (called Block B in 2016) was ready for the start of the 1955 school year.

[39][1] In 1954 the type was improved by replacing the proliferation of stumps in the understorey with a timber truss that spanned the width of the classroom and provided an unimpeded play space.

Vocational education was a Queensland Government priority to support the development of primary industries; and after World War I this led to the establishment of a variety of subjects.

[55][1] When completed, the ground floor of Block C included: a store under the stairs (which were enclosed with brick and wired glass, with a flower box to the north) at the eastern end of the building; girls toilet and locker room; store and staff toilet; covered recreation and assembly area; and a dais (raised area) at the west end.

[74][75] Just north of the brick piers, there is another pedestrian gateway in 2016, with a metal archway reading "Harristown State High School", mounted on  concrete plinths.

This building presents itself as a keystone for the campus' front of house facilities, ideal for its corner setting providing connection and street presence for the school.

Most soffits are lined in flat sheeting with rounded cover strips, and all bag racks are timber-framed with profiled metal exterior cladding.

[1] The administration block is a lowset, single-story, timber-framed and masonry structure that is sheltered by a low-pitch gable roof clad in profiled metal sheeting.

[1] The original open-plan internal layout of the northern wing is discernible, although lightweight partitions now enclose some of the former circulation and waiting areas.

The walls and ceilings of most classrooms are lined in flat sheeting with rounded cover strips, and timber portal trusses are visible within the ground floor spaces.

The ground floor spaces and stairs at the eastern and western ends are enclosed by face brick walls and the southern eaves are supported by timber brackets.

The ground floor interior comprises eastern amenities, and a former recreation area to the west that is now enclosed to form a large storage and office space and a classroom.

The floor-level of the storage and office space is set above the remainder of the floor, and the easternmost toilets have been converted to locker enclosures, with timber framing retained and indicating their original location.

[1] The Oslo lunch canteen stands to the south of the west end of Block C. It is a small, rectangular building with southern, eastern and western walls of face brick below sill height and fixed, wired glazing above.

[1] The verandah has a raked ceiling lined in flat sheets with rounded cover strips, square timber posts and bag racks that form the balustrade.

The eastern and western end walls and some ground floor enclosures are facebrick, with the remainder of the building's exterior clad in flat sheets and profiled metal.

Concrete stairs, located at the eastern and western ends of the building, provide access to the first-floor verandah and classrooms and have metal handrails.

A brick wall has been removed from the classroom space, and a modern partition has been added at the eastern end to form an additional store room.

Metal-framed shade structures with profiled metal roof cladding and concrete slab floors form covered connections between the significant school buildings.

Other mature trees, planted during the school's first 15 years of operation, are located along South Street; in an east–west line south of Block J; and in a line extending southeast from the end of Block K.[1] A decorative metal archway set on concrete plinths is located at the Hennessey Street entrance and features "HARRISTOWN STATE HIGH SCHOOL" in metal lettering.

[1] The layout of the administration and classroom blocks, the covered links between them and associated open spaces, reflect the early 1950s introduction of master planning, which provided for ordered growth from a nucleus.

These include its 1950s site planning; range of highset and lowset timber-framed teaching buildings of standard and individual designs that incorporated understorey play areas, verandahs, and classrooms with high levels of natural light and ventilation; and a generous, landscaped site with mature shade trees and assembly and sports areas.

Both buildings retain their: highset character with visible trusses under; large banks of south-facing timber-framed awning windows, with centre-pivoting fanlights; clerestory lighting above the northern verandah roof; and 24-foot (7.3 m) wide classrooms.

They typically retain significant and enduring connections with former pupils, parents, and teachers; provide a venue for social interaction and volunteer work; and are a source of pride, symbolising local progress and aspirations.