Vũng Rô Bay (Vietnamese: Vịnh Vũng Rô) is a small bay in Phú Yên Province, Vietnam. Vũng Rô is located in the commune (xã) of Hòa Xuân Nam, Đông Hòa District, Phú Yên Province, located at the edge of Cả Pass mountains. The bay is the natural border of provinces of Phú Yên and Khánh Hòa.
Vung Ro covers an area of 16.4 square kilometres (6.3 sq mi) and is surrounded by Đèo Cả, Đá Bia and Hòn Bà mountains from the north, the east and the west respectively. There are some fine sand seasides by the bay. The bay is home to coral reefs.
In February 1965 the bay was the site of Vũng Rô Bay Incident.
In July 1966 the U.S. Army secured the area as part of Operation John Paul Jones and the 39th Engineer Battalion constructed a small port facility here to support U.S. Army operations in the area and relieve the logistical pressure on Tuy Hòa. The base was named Port Lane after LTC Ernest Lane who was killed in action on 18 May 1966.
Coordinates: 12°52′N 109°26′E / 12.867°N 109.433°E