"God Defend New Zealand" became New Zealand's second national anthem, on equal standing with "God Save the King", which had been the traditional anthem since 1840.

"God Defend New Zealand" is one of two national anthems of New Zealand, the other being "God Save the King". Legally the two have equal status, but "God Defend New Zealand" is more commonly used. Originally written as a poem, it was set to music as part of a competition in 1876. Over the years its popularity increased, and it was eventually named the second national anthem in 1977. It has English and Māori lyrics, with slightly different meanings. Since the late 1990s, the usual practice when performed in public is to perform the first verse of the national anthem twice, first in Māori and then in English.

A national anthem is a patriotic musical composition symbolizing and evoking eulogies of the history and traditions of a country or nation. The majority of national anthems are marches or hymns in style. American, Central Asian, and European nations tend towards more ornate and operatic pieces, while those in the Middle East, Oceania, Africa, and the Caribbean use a more simplistic fanfare. Some countries that are devolved into multiple constituent states have their own official musical compositions for them ; their constituencies' songs are sometimes referred to as national anthems even though they are not sovereign states.

"God Save the King" is de facto the national anthem of the United Kingdom. It is one of two national anthems of New Zealand and the royal anthem of the Isle of Man, Australia, Canada and some other Commonwealth realms. The author of the tune is unknown and it may originate in plainchant, but an attribution to the composer John Bull has sometimes been made.