The Chatham Cup is New Zealand's premier knockout tournament in men's association football. It is held annually, with the final contested in September. The current champions of the Chatham Cup are Wellington Olympic, who defeated Auckland United in the 2025 final.

The Chatham Cup is contested by teams from throughout New Zealand, and has been held annually since 1923 with the exception of 1937, 1941–44 and 2020. Typically between 120 and 150 teams take part, with extra time and penalty shoot-outs used to decide matches which end in ties. In the past, replays were used, and in the early years of the competition the number of corners won during a game decided tied matches.

The cup itself was gifted to the then New Zealand Football Association by the crew of HMS Chatham as a token of appreciation for the hospitality they had encountered on a visit to New Zealand. The cup, which cost £150, was presented to NZFA President Sir Charles Skerrett by Captain Cecil Burnaby Prickett on board the Chatham on 14 December 1922. The actual trophy is modelled on the FA Cup.

The most successful teams in the Chatham Cup have been Christchurch United and Mount Wellington (seven wins, two of them since amalgamation with Auckland University); North Shore United has won six times. Most of the competition's winners have come from the main centres of Auckland, Wellington and Christchurch, though teams from Dunedin, Gisborne, Hamilton, Masterton, Nelson, and Napier have also won the competition, while the inaugural champions were from the small settlement of Seacliff, with many of the team being staff from the nearby psychiatric hospital.

The competition has been held every year since 1923 with six exceptions: the 1937 competition was cancelled due to a lack of entrants (only 12 teams applied to take part), four competitions (from 1941 to 1944) were cancelled due to World War II, and the 2020 competition was cancelled because of COVID-19.

Many of the early winners of the competition no longer exist, as competition was not effectively organised in New Zealand until the advent of a national league in 1970, and still remains largely amateur to this day. Many early New Zealand clubs have amalgamated with their neighbours or disbanded.

Prior to 1970, the final was held between the winners of separate North Island and South Island tournaments, with national semi-finals often being referred to as "Island finals".

In the early years of the competition, each regional association found its own champion to represent that region in the Chatham Cup, leading to confusion in many of the early records with regional finals, island finals, and the national final all often simply being referred to in contemporary reports as "finals". Further confusion is caused by the incomplete nature of many of the early competition records. It is only since the first publication of an annual New Zealand football yearbook in 1965 that any systematic record-keeping began to take place; earlier match reports and statistics are complete only inasmuch as the vagaries of newspaper sports reporting allowed.