The Roman Catholic Diocese of Nha Trang () covers an area of 9,486 kmò in the Provinces of Ninh Thuan and Khanh Hoa in Vietnam and is a suffragan diocese of the Archdiocese of Huế. The creation of the diocese in present form was declared November 24, 1960.
By 2013, the diocese of Nha Trang had about 200,385 Catholics (11.2% of the population), 191 priests and 90 parishes.
Christ the King Cathedral in Nha Trang has been assigned as the Cathedral of the diocese.