John Andrew Millar was a New Zealand politician of the Liberal Party from Otago.

The New Zealand Liberal Party was the first organised political party in New Zealand. It governed from 1891 until 1912. The Liberal strategy was to create a large class of small land-owning farmers who supported Liberal ideals, by buying large tracts of Māori land and selling it to small farmers on credit. The Liberal Government also established the basis of the later welfare state, with old age pensions, developed a system for settling industrial disputes, which was accepted by both employers and trade unions. In 1893 it extended voting rights to women, making New Zealand the first country in the world to enact universal adult suffrage.