德属西南非洲（德语：Deutsch-Südwestafrika），1884年至1915年德意志帝国的殖民地之一。德属西南非洲具有835100平方公里的面积，这是德意志帝国大陆在当时欧洲面积的1.5倍的规模。

1915年，在一战期间，德属西南非洲被英国和南非军队入侵。在战争结束后，其行政被南非联邦（大英帝国的一部分）接管，和领土在国际联盟的授权管理作为西南非洲。它于1990年成为独立的纳米比亚。

German South-West Africa (German:Deutsch-Südwestafrika, DSWA) was a colony of the German Empire from 1884 until 1915. With an area of 835,100 km², it was one and a half times the size of the mainland German Empire in Europe at the time.

In 1915, during the First World War, German South-West Africa was invaded by the Western Allies in the form of South African and British forces. After the war its administration was taken over by the Union of South Africa (part of the British Empire) and the territory was administered as South-West Africa under a League of Nations mandate. It became independent as Namibia in 1990.