Chief Post Office, Christchurch, Category 1 historic post office in Cathedral Square, Christchurch, New Zealand

The Chief Post Office stands at 31 Cathedral Square, in the square's southwest corner. Built of brick in an Italianate style with classical and Venetian Gothic elements, it has pointed arches on the upper windows and a third gabled bay added to the north frontage in 1907. It is a Category I heritage building.

The building was designed by William Henry Clayton, New Zealand's only Colonial Architect, and its foundation stone was laid on Queen's Birthday, 24 May 1877, by Edward Richardson. Clayton died soon after and Pierre Finch Martineau Burrows supervised completion in 1878; it opened on 14 July 1879. In 1881 New Zealand's first telephone exchange was installed here, and in 1907 a third gable was added to the west.

The building served as a vital meeting point where residents conducted postal business and made telephone calls in the heart of the city. It remains a landmark that connects visitors to how communities once gathered around such essential services.

The building stands at 31 Cathedral Square, in the southwest corner of the square. The road in front of it was closed during the square's 1992 redesign, so the entrance is reached on foot. Repairs and strengthening begun in the early 2020s were planned to reopen the building in stages from 2023, but the company behind the plan entered voluntary administration in August 2024; check locally before visiting.

In 1881 New Zealand's first telephone exchange was installed in this building, which had opened as the Government Buildings in 1879. The 1907 extension added a third gable to the west, giving the north frontage its present form; until then the building had two symmetrical façades.