The Baiuvarii, Bavarii, or Bavarians (Bajuwaren) were a Germanic people. The Baiuvarii had settled in modern-day Bavaria (which is named after them), Austria, and South Tyrol by the 6th century AD, and are considered to be the ancestors of modern-day Bavarians, Austrians and South Tyroleans. It is believed that they spoke an early version of the Bavarian language.
The name of the Baiuvarii is also spelled Baiuvari. It probably means "men from Bohemia". The placename Bohemia is believed to be connected to that of the Boii, a Celtic people who partly left the region before the Roman era and then dominated by Germanic peoples. The Baiuvarii gave their name to the region of Bavaria.
The language of the Baiuvarii is classified as Germanic. It is uncertain whether they originally spoke an East Germanic or West Germanic language. Early evidence on the language of the Baiuvarii is limited to personal names and a few Runic inscriptions. By the 8th century AD, the Baiuvarii were speakers of an early form of the Austro-Bavarian language within the West Germanic family.
The name is first attested in Latin sources in the 6th century AD.
Notably, the early 6th century biography of Severinus of Noricum describes the region without mentioning them.
One of the earliest references to the Baiuvarii is the Frankish Table of Nations from about 520, which describes them as a people with kinship to the Burgundians, Thuringians and Lombards.
In his Getica (551), Jordanes wrote that the Suebes people under the rule of the 5th century Hunimund had lived across the Danube from Dalmatia and Pannonia with the Franks on their west, Thuringians to their north, and Burgundians to their south, and the Baibaros to their east, who may have been the Bavarians.
In a poem about a pilgrimage to Augsburg in 565, Venantius Fortunatus mentions the land Baioaria on the river Lech, which north flows from the Austrian alps to the German Danube. They were between the Allemanni on the Danube and the Breones who were based near the river Inn.