The Surabaya metropolitan area or Greater Surabaya, known locally as Gerbangkertosusila, is a metropolitan area in East Java, Indonesia. It is the country's second-largest metropolitan area, after Jakarta metropolitan area. Gerbangkertosusila had also been used in presidential decree to refer to larger region which include Jombang, Bojonegoro, and Tuban.

East Java is a province of Indonesia located in the easternmost third of Java island. It has a land border only with the province of Central Java to the west; the Java Sea and the Indian Ocean border its northern and southern coasts, respectively, while the narrow Bali Strait to the east separates Java from Bali by around 2.29 kilometres (1.42 mi). Located in eastern Java, the province also includes the island of Madura, as well as the Kangean islands and other smaller island groups located further east and Masalembu archipelagos in the north. Its capital is Surabaya, the second largest city in Indonesia, a major industrial center and also a major business center. Banyuwangi is the largest regency in East Java and the largest on the island of Java.