The Regierungsbezirk Weser-Ems was the most westerly of the four administrative regions of Lower Saxony, Germany, bordering on the Dutch provinces of Groningen, Drenthe and Overijssel. It was established in 1978 by merging the former regions Osnabrück, Aurich, and Oldenburg. It was formally dissolved by the end of 2004 along with the other Regierungsbezirke of Lower Saxony as part of an effort to optimize the administrative system of the state.