Santa Josefa, officially the Municipality of Santa Josefa (; ), is a municipality in the province of Agusan del Sur, Philippines. According to the 2020 census, it has a population of 26,432 people, making it the least populated town in the province.
Santa Josefa is located at , making it the province's most southerly settlement.
According to the Philippine Statistics Authority, the municipality has a land area of constituting of the total area of Agusan del Sur.
Santa Josefa is classified as Type II climate which has no dry season but with pronounced maximum rain period occurring from December to January.
Santa Josefa is politically subdivided into 11 barangays. Each barangay consists of puroks while some have sitios.
In the 2020 census, Santa Josefa had a population of 26,432. The population density was .
Santa Josefa's main products are rice and corn.