米西奥内斯省（Misiones）为南美国家阿根廷二十三省之一，位于阿根廷东北部（如右图之14位置），该省首府为波萨达斯（Posadas）。

Misiones (Spanish pronunciation: [miˈsjones], Missions) is one of the 23 provinces of Argentina, located in the northeastern corner of the country in the Mesopotamiсa region. It is surrounded by Paraguay to the northwest, Brazil to the north, east and south, and Corrientes Province of Argentina to the southwest.