The Minister of Internal Affairs is a minister in the New Zealand Government with responsibility over the Department of Internal Affairs. The position of Minister of Internal Affairs has existed since the Department of Internal Affairs replaced the Colonial Secretary's office from 19 November 1907. The responsibilities of the office have been progressively reduced as other ministerial roles have been spun-off from the Department of Internal Affairs. Today his or her remit includes internal security and administering applications for citizenship.

Ministers in the New Zealand Government are members of Parliament (MPs) who hold ministerial warrants from the Crown to perform certain functions of government. This includes formulating and implementing policies and advising the governor-general. Ministers collectively make up the executive branch of the New Zealand state. The governor-general is obliged to follow the advice of the prime minister on the appointment and dismissal of ministers.