Roslyn Post Office was built in 1907 and officially opened in 1908. It is historically and architecturally significant for the Borough of Roslyn at a time when postal communication was paramount for New Zealand. It was built during a post office building boom between 1900 and 1914 and is one of the remaining smaller post offices which, with some variation, were built all over New Zealand. Built with a striking tower in Edwardian Baroque style, it remains in the suburb of Roslyn, little altered.

Both iwi history and archaeological evidence show Māori occupation in the Ōtākou / Otago region since the 12th century. Today, Kāi Tahu mana whenua is recognised over a large part of Te Wai Pounamu. Kāti Māmoe and Waitaha shared occupation is always acknowledged. The hapū Kāi Te Pahi, Kāti Moki, and Kāti Taoka still maintain their presence and responsibility as kaitiaki in this region.

The postal service in New Zealand began in 1840, and the first post office in Dunedin opened in 1855. By the early twentieth century the Post and Telegraph Department had become one of the major government departments, with branches in all the main centres. Roslyn in Dunedin operated as a Borough, complete with its own mayor and council, which was formed in 1877. An early post office operated on High Street (later renamed Highgate) until 1907. The need of a new post office for Roslyn was discussed at a council meeting where the mayor labelled the current post office as a “disgrace”. The council decided to write to the Hon J. A Millar, to request a new post office. Millar successfully managed to secure a surplus of money for the Roslyn Post Office in 1905. The Public Works Department was asked to submit plans for a “suitable building on the vacant land in front of the old building”.

John Campbell (1857-1942), Government Architect, designed the Post Office, along with many other commercial buildings. Campbell oversaw the architectural design of government buildings until his retirement in 1922, holding the title of ‘government architect’ from 1909. Campbell established the architectural style of Edwardian Baroque as the official architectural style for government buildings in New Zealand in the early twentieth century. Between 1900 and 1914 a post office boom occurred and due to the large amount of work, Campbell developed two models for smaller post offices which, with some variation, were built throughout New Zealand. Erecting new post offices was influenced by the completion of the main trunk line in the North Island along with the replacement of old timber buildings and building in more permanent materials and the spread of telegraphic communication throughout New Zealand.

The Roslyn Post Office was constructed in 1907 by contractor Robert Orr at a cost of £1344 ($278,916 today). Construction was completed on 18December 1907 and it officially opened on 25 February 1908. Roslyn’s post office was built with an “imposing” clock tower and most of the towers of the post offices of this design no longer exist with the Roslyn Post Office being one of six that remains. The roof was originally Marseilles tiles. The space included a telephone bureau, a mail room and the postmaster's room with a permanent postmistress. Accommodation was on the first floor.

Postal services ceased on 5 February 1988 but the building continued to house a Post Bank until 20 March 1992. Since the 1990s, it has housed a Real Estate’s office downstairs, and the second floor has remained as residential accommodation. In 2018, the building had an exterior repaint and a new roof, as well as kitchen and bathroom upgrades. The building with its rich Baroque decoration became a focal point of Roslyn and these post offices for many New Zealanders represent the archetypal New Zealand post office building.