State Highway 63 is a state highway located in the northern parts of the South Island of New Zealand. It is 117 km long and runs between the settlements of Renwick and Kawatiri Junction via Saint Arnaud, providing a bypass of the city of Nelson. Despite being a convenient link between the West Coast and Marlborough, and being a relatively straight highway along most of its length, it is only classified by the NZTA as a secondary collector highway.