This entry is about the Teutonic people, not to be confused with the Teutonic Knights.

The Teutons (Teutones) were mentioned as a Germanic people in early historical writings by Greek and Roman authors. Their homeland was given as Thy in Jutland, the top of the western peninsula of modern Denmark. There is debate as to whether they were a Celtic or Germanic people since the name Teutones itself appears to be Celtic; Strabo and Velleius, however, counted them among the Germanic tribes. German historians did not associate the name Teutons with their Germanic ancestors until the 13th century.

More than 100 years before the birth of Christ, many of the Teutoni, as well as the Cimbri, migrated south and west to the Danube valley, where they encountered the expanding Roman Empire.

During the late 2nd century BC, the Teutons are recorded as marching south through Gaul along with their neighbors, the Cimbri, and attacking Roman Italy. After several victories for the invading armies, the Cimbri and Teutones were finally defeated by Marius in 102 BC at Aquae Sextiae (near present-day Aix-en-Provence).

The terms "Teuton" and "Teutonic" have sometimes been used in reference to all of the Germanic peoples. "Teut" is an Indo-European word for people, and is not only found in German "deutsch" (=German) and Old Norse "thjod" people, but also in the romance word for all (as in Latin totum, tout in French, or todo in Spanish). It is therefore sometimes used as a synonym to proto-Germanic.