The Chief Post Office or Christchurch Central Post Office, originally known as the Government Buildings, is located in Cathedral Square, Christchurch, New Zealand. The building was initially a post office with Immigration, Customs and Public Works departments. The Government Buildings were later replaced by the new Government Buildings opened in 1913, and the Chief Post Office remained on-site. In 1881, New Zealand’s first telephone exchange was installed in the building. Post services were offered from the building until 2000 when it was re-purposed to house a Christchurch tourist information centre and a restaurant, café and offices. Following the 2011 Christchurch earthquake the building closed. In the early 2020s repairs and strengthening took place. The building was planned to reopen in 2023 in stages, and eventually include a restaurant, shops, and a visitor information centre, under the name "The Grand". The structure is registered with Heritage New Zealand as a Category I heritage building.

Cathedral Square, locally known simply as the Square, is the geographical centre and heart of Christchurch, New Zealand, where the city's Anglican cathedral, ChristChurch Cathedral is located. The square stands at the theoretical crossing of the city's two main orthogonal streets, Colombo Street and Worcester Street, though in practice both have been either blocked off or detoured around the square itself. The square was badly damaged in the February 2011 Christchurch earthquake.