An Nhơn is a district-level town of Bình Định Province in the South Central Coast region of Vietnam. As of 2003 the district had a population of 187,737. The district covers an area of 255 km². The district capital is Bình Định. It has a population density of 779 people per km², and they are distributed unevenly, with high concentrations in the wards of Bình Định and Đập Đá. 55.50% of the population in the district are of working age.
An Nhơn district lies on a plain at 13°49'N and 109°18'E. It is located along the National Route 1A 20 km from the city of Quy Nhơn. The north of the district borders Phù Cát, the east of the district borders Tuy Phước, the west borders Tây Sơn, and the south-west borders the mountainous district of Vân Canh.