The courthouse at Waimate, now the home of the Waimate Museum, is a elegant neo-classical building, which dominates the streetscape and stands as a reminder of the town's heyday. The local area was known to Maori as Te Waimatemate, which has been shortened over the years to Waimate. When Michael Studholme (1834-1886) came to select land for a sheeprun in the area in 1854, he found Te Huruhuru (?-1861) and his people residing in a village on the west bank of the Waimate River. Studholme entered into an agreement with Te Huruhuru, which allowed Studholme to settle in the area. This opened Te Waimatemate up to further Pakeha settlers, who were encouraged by the plentiful supply of timber available from the local bush. Waimate, the settlement, developed as a sawmilling town with 300 residents by 1864. The first magistrate, Mr Belfield Woollcombe (1816-1891), was appointed to Waimate in 1865 and the first courthouse was constructed in 1866-1867. In 1878 a fire, which burnt for eight days, destroyed most of the bush and the town went into a slump. Despite this setback the construction of the new courthouse in Sherman Street went ahead the following year to replace the earlier court which had become 'smokey, unfurnished and miserable'.

The new courthouse was designed by P.F.M. Burrows (1842-1920), an architect who arrived in New Zealand around 1863 and who worked under W.H. Clayton (1822-1877) in the Colonial Architect's Office. When Clayton died in 1877, Burrows took over his duties, although he did not receive the official designation of Colonial Architect. He was responsible for many of the smaller post offices and courthouses throughout New Zealand. The courthouse at Waimate was erected by builder H. McCormick and it was built on land gazetted for police purposes in 1865.

Construction began in 1879 and the courthouse formally opened in July 1880. Built in brick covered by plaster, the courthouse consists of a central hall, which houses the courtroom, flanked by two single-storeyed wings. The central hall is around one and a half storeys high and is topped by a triangular pediment which features the date of the building and the words 'Court House' surmounted by a crown. The main entrance is situated in the middle of the central wing under a small portico. The single-storey side wings have walls capped by masonry parapets, hipped roofs and once housed the offices associated with the court. This layout is typical of nineteenth century courthouses in both New Zealand and Australia, as are the classical references. The use of the Classical style in courthouses conveyed both gravitas and dignity thought appropriate as well the ideals of justice associated in popular memory with the ancient Greeks and Romans. In Waimate it was also no doubt influenced by the Classical style of the County Chambers erected the year before and designed by Oamaru architects, Forrester and Lemon. They too were impressed by the courthouse design and, according to architectural historian Conal McCarthy, used elements of it in their design of the Oamaru Courthouse (1882-1883). Although after its opening two difficulties were found with the new courthouse; sound echoed so that it was difficult to hear what speakers were saying and, with its six metre ceiling, the courtroom was extremely difficult to heat in winter, its outward appearance impressed those who saw it.

As with all courthouses the one in Waimate is associated with many events of local significance. One in particular relates to the passing Land for Settlements Act in 1892. The immense neighbouring estate, Waikakahi, owned by Allan McLean (1822-1907), was sold to the government after some pressure from the then Minister of Lands, John McKenzie. It became the first property sold to the Crown under the Public Lands Act and the subsequent ballot of sections was carried out at the Waimate Courthouse. The influx of new settlers from the splitting up of Waikakahi increased both the population and boosted the town's economy.

In October 1979 the courthouse was closed by the Department of Justice, in conjunction with the closure of more than 20 other courthouses throughout New Zealand. The Waimate Museum Trust Board requested that the building be passed to it, for use as a museum, as its premises in Harris Street were too small. The museum took over the day-to-day control of the building from 1981 while the government finalised its decision about the fate of the building. Eventually the courthouse and surrounding land was declared an historic reserve and the Museum Trust Board was appointed to control and manage the former courthouse and land.

The courthouse itself remains relatively unaltered, although the chimneys were removed because of safety concerns, as were the two fir trees which were damaged in a 1975 storm. The museum retained the magistrates' bench in the courtroom and the overall layout of the building, and visitors receive a clear impression of how the courtroom used to be. The stables and toilets from the courthouse survive at the rear of the property. Over the years the Waimate Museum has moved other buildings onto the site, including a small cottage built in totara and the former jail. It has also built large sheds to the rear of the property to house its collection of historic machinery. A new picket fence was erected along the Sherman Street frontage, the design of which was based on historical photographs and a old gas lamp post was relocated from the former museum buildings to carry the entrance sign.

The Waimate Museum, once the town's courthouse, is significant as a beautiful building and a major feature of the townscape. Now painted white with blue trim, the courthouse is surrounded by mature trees. It has served as a courthouse for 100 years and its scale and elegance indicates the historical status of Waimate as a major town. It was designed by nationally recognised architect, Burrows, and is an impressive example of his work. It is arguably one of the finest courthouses to survive in New Zealand.