First attested as a Gothic name in the 5th century, it became widespread in the Germanic-speaking world, not least due to its most famous bearer, Theodoric the Great, king of the Ostrogoths.

The name was Latinized as Theodoricus or Theodericus, originally from a Common Germanic form *Þeudarīks ("people-ruler") from *þeudō ("people") and *rīks, which would have resulted in a Gothic *𐌸𐌹𐌿𐌳𐌰𐍂𐌴𐌹𐌺𐍃 (*þiudareiks).

[1] Anglicized spellings of the name during Late Antiquity and the Early Middle Ages include Theodoric, Theoderic, Theudoric, Theuderic.

The earliest record of the name is in a Roman-era (3rd century) inscription, discovered in 1784 in Wiesbaden (at the time known as Aquae Mattiacorum in Germania Superior), edited in Codex inscriptionum romanarum Danubii et Rheni as no.

The notability of the name is due to Theoderic the Great, son of Theodemir, king of the Ostrogoths (454–526), who became a legendary figure of the Germanic Heroic Age as Dietrich von Bern.

The Middle High German legend of Dietrich von Bern is based on the historical Theodoric, king of the Ostrogoths.

Similarly, the Scandinavian Tjodrik is attested for the 12th century, but it is replaced by the Low German forms Ditrik, Dirk in the late medieval period.