Prosperidad is a first class municipality in the province of Agusan del Sur, Philippines. It is the capital of the province. According to the 2010 census, it has a population of 76,628 people. Prosperidad was created on June 18, 1960 by virtue of Republic Act No. 2650.
Prosperidad is the venue of the "Naliyagan Festival", an annual event celebrated by the entire province of Agusan del Sur.
Prior to the Spanish Colonial Period, a Manobo settlement thrived at the junction of the Sianib and Gibong River. This settlement was known to the natives as Culilay.
During the Spanish Colonial Period, the missionaries discovered the settlement and soon began the Christianization of the Manobos. The natives were given Christian names and the settlement was renamed from Culilay to San Juan.
At the start of the American Period, San Juan was again renamed Las Navas but the name was short-lived as the place underwent another change in name – from Las Navas to Prosperidad derived from the word Prospero or “progressive” as the place experienced growth and prosperity during the time of American Governor Zapanta who coined the name which to this day is the name of the Municipality.