The Old Post Office in Saint John holds the distinction of being a Local Historic Place due to its architectural significance and its previous function as a post office. It is part of a series of Second Empire government buildings constructed between 1877 and 1881, following the devastation of two-thirds of Saint John in a fire in 1877. Built in 1881, the Old Post Office exemplifies institutional Second Empire architecture from Saint John’s reconstruction era, featuring a mansard roof, intricate attic and dormer windows, rectangular massing, and various arched doors and windows. The building’s design bears resemblance to those from the U.S. government’s Post Civil War Construction Program.

The sloping terrain allowed for a three-storey building and an attic above Prince William Street, with an additional two basement storeys on the Water Street side. The Old Post Office was the first iron frame building in the City of Saint John, and the use of iron and stone symbolized the city’s determination to rebuild after the fire. Thomas Scott, the chief architect of the Public Works Department, led the design process, and Matthew Stead, a local architect, contributed to revisions of the original plan.

Located within the Trinity Royal Preservation Area, the Old Post Office is part of the Prince William Street Historic Streetscape, a federally protected group of buildings characterized by their rare concentration of primarily late 19th-century architecture. Known as the “Wall Street of Saint John,” the area comprises major public buildings, banks, hotels, insurance, shipping and legal offices, and the Seamen’s Institute.

The Old Post Office is also notable for serving as the main post office in Saint John from 1881 to 1915. It was built on the foundation of the previous post office, which was destroyed in the 1877 fire. A new building replaced the Old Post Office in 1915, which was then repurposed for Federal Government offices before being sold to the city for various uses.

In 2015, Edmonton developers Rob Fediuk and John Kupchenko purchased the property for $2-million and planned to transform the upper floors into seven condominium units, renaming the building “The Royal.”