Knox College is a selective residential college, founded and run by the Presbyterian Church of Aotearoa New Zealand and affiliated with University of Otago in Dunedin, New Zealand. The college is set in a 4.57 hectares landscaped site in Opoho on the opposite side of the Dunedin Botanic Gardens from the university. It is named after John Knox, a sixteenth century leader of the Scottish Reformation, whose efforts in establishing a universal system of free education comprising both academic learning and character formation had a profound influence, not just in Scotland, but internationally, as subsequent generations of Scottish settlers, products of the Scottish Enlightenment, emigrated to far-flung corners of the globe, including New Zealand, taking with them a deep-seated belief in the benefits of applied knowledge and a broad and liberal education. Those strong Scottish Presbyterian foundations are something that Knox College has in common with the university to which it is affiliated. They are depicted on the college's Coat of Arms in the form of a blue St Andrew's Cross. Superimposed on the St Andrew's Cross is the image of a white dove in flight, carrying an olive branch in its mouth, a symbolic depiction of the flood myth in Genesis 8, wherein the olive-branch-bearing dove is a symbol of life and peace. The college motto, Gratia et Veritas (Latin), or Grace and Truth (English), comes from the Prologue to the Gospel according to Saint John.

The majority of first year students at the University of Otago's Dunedin campus stay in one of the fourteen residential colleges, alongside a smaller number of senior students and postgraduates. These colleges provide food, accommodation, social and welfare services, as well as some degree of additional academic support, particularly for the largest papers.