A number of introduced species, some of which have become invasive species, have been added to New Zealand's native flora and fauna.

Both deliberate and accidental introductions have been made from the time of the first human settlement with several waves of Polynesian people at some time before the year 1300, followed by Europeans after 1769. Almost without exception, the introduced species have been detrimental to the native flora and fauna but some, such as sheep and cows and the clover upon which they feed now form a large part of the economy of New Zealand.

Biosecurity New Zealand maintain registers, lists and indexes of species that are invasive, potentially invasive, or a threat to agriculture or biodiversity.