The 1973 Chatham Cup was the 46th annual nationwide knockout football competition in New Zealand. The organisation of the cup was changed from previous years, with early stages being run in three large zones (northern, central, and southern), rather than by individual associations as had previously been the case. National League teams received a bye until the later stages of the competition. In all, 103 teams took part in the competition. Note: Different sources give different numberings for the rounds of the competition: some start round one with the beginning of the regional qualifications; others start numbering from the first national knock-out stage. The former numbering scheme is used in this article.