The Oldenburg Münsterland, otherwise called Oldenburger Münsterland or Oldenburgisches Münsterland, is a region in Lower Saxony, Germany and the administrative area that comprises the federal districts of Cloppenburg and Vechta. Unofficially, it is also called Südoldenburg; its inhabitants call themselves Südoldenburger accordingly. The denominative Oldenburger Münsterländer is rather uncommon.
In 1252, the Prince-Bishopric of Münster acquired the former County of Ravensberg-Vechta. With the conquest of the former Tecklenburg office of Cloppenburg in 1400, the common history of today's Oldenburg Münsterland in the Lower Chapter of Münster began. In 1668, the Bishop of Münster also gained ecclesiastical sovereignty over Lower Saxony. As a result of the Reichsdeputationshauptschluss of 25 February 1803, the Protestant Duke of Oldenburg gained state power over the offices of Cloppenburg and Vechta, whose population has remained predominantly Roman Catholic to this day.
During the so-called French period (1811–1813), the Oldenburg Münsterland was administrated by the French-Hanseatic Département de l'Ems-Supérieur (Department of the Upper Ems). Until 1946, the Oldenburg Münsterland remained part of the Grand Duchy of Oldenburg or the Free State of Oldenburg (since 1919). Since 1946, the Oldenburg Münsterland has belonged to the German state of Lower Saxony and includes the area of the federal districts of Cloppenburg and Vechta.