Gustaf Kossinna (28 September 1858 in Tilsit – 20 December 1931 in Berlin) was a linguist and professor of German archaeology at the University of Berlin. Along with Carl Schuchhardt he was the most influential German prehistorian of his day, and was creator of the techniques of Siedlungsarchaologie, or "settlement archaeology." His nationalistic theories about the origins of the Germanic peoples influenced aspects of Nazi ideology; nevertheless, he was rejected by the party as their official prehistorian. That distinction was given to Carl Schuchhardt, the rival archaeologist who beat Kossinna in successfully assessing the value of the Eberswalde Hoard, the largest treasure ever discovered in German history, upon its discovery in 1913.

Kossinna was a Germanized Mazur. He was born in Tilsit, East Prussia, Kingdom of Prussia. His father was a teacher at the secondary-school level. As a child he learned Latin and piano.

As a university student he matriculated at a number of universities, studying classical and Germanic philology in Göttingen, Leipzig, Berlin and Strassburg. He was influenced greatly by K. Muellenhoff, who encouraged him to research the origins of Indo-European and Germanic culture. He obtained his doctorate at Strasbourg in 1887 in the subject of the early records of the high-Frankish language. From 1888 to 1892 he worked as a librarian. In 1896 his ideas were expressed in his lecture "The Pre-historical Origins of the Teutons in Germany". In 1902 he was appointed as Professor of German archaeology at the University of Berlin. In the same year he identified the Proto-Indo-Europeans with the north German Corded Ware culture, an argument that gained in currency over the following two decades. He placed the Indo-European urheimat in Schleswig-Holstein.

Kossinna is a village in Sri Lanka. It is located within Central Province.