The Ostrogoths (Latin: Ostrogothi, Austrogothi) were a Roman-era Germanic people who in the 5th and 6th centuries established one of the two major Gothic kingdoms within the Western Roman Empire. They drew on large Gothic populations settled in the Balkans since the 4th century and rose to prominence under Theodoric the Great, who in 493 founded the Ostrogothic Kingdom in Italy after defeating Odoacer.

Theodoric belonged to the Amal dynasty, which had gained power in Pannonia after the collapse of Attila’s Hunnic empire. Backed by the Byzantine emperor Zeno, Theodoric invaded Italy and established his rule from Ravenna, preserving Roman administration, law, and culture while governing Goths and Romans under parallel systems. His reign marked the height of Ostrogothic power and stability in Italy.

After Theodoric’s death in 526, dynastic instability weakened the kingdom. In 535, Emperor Justinian I launched the Gothic War (535–554), aiming to restore imperial authority in the West. The Ostrogoths, revitalized under Totila, temporarily regained much of Italy, but Totila was killed at the Battle of Taginae in 552. The protracted war devastated the peninsula, and the Ostrogothic state collapsed by 554. Survivors were absorbed into the Lombards, who established their own kingdom in Italy by 568.

The Ostrogoths were associated with the earlier Greuthungi mentioned by Roman authors such as Ammianus Marcellinus, and later identified by the historian Jordanes with the realm of Ermanaric in the 4th century. Ancient sources often referred to them simply as “Goths,” but modern scholarship distinguishes them as one of the two main branches of the Gothic peoples, alongside the Visigoths.

The Ostrogoths were one of several peoples referred to more generally as Goths. The Goths appear in Roman records starting in the third century, in the regions north of the Lower Danube and Black Sea. They competed for influence and Roman subsidies with peoples who had lived longer in the area, such as the Carpi, and various Sarmatians, and they contributed men to the Roman military. Based on their Germanic language and material culture, it is believed that their Gothic culture derived from cultures from the direction of the Vistula river in the north, now in Poland and originally from Götaland (in English Western and Eastern Gothlands) and Gotland in present-day Sweden. By the third century, the Goths were already composed of sub-groups with their own names, because the Tervingi, who bordered on the Roman Empire and the Carpathian Mountains, were mentioned separately on at least one occasion.

The Ostrogoths, not mentioned until later, are associated with the Greuthungi who lived further east. The dividing line between the Tervingi and the Greuthungi, was reported by Ammianus to be the Dniester River, and to the east of the Greuthungi were Alans living near the River Don.

The Ostrogoths in Italy used a Gothic language which had both spoken and written forms, and which is best attested today in the surviving translation of the Bible by Ulfilas. Goths were a minority in all the places they lived within the Roman empire, and no Gothic language or distinct Gothic ethnicity has survived. On the other hand, the Gothic language texts which the Ostrogothic kingdom helped preserve are the only eastern Germanic language with "continuous texts" surviving, and the earliest significant remnants of any Germanic language.

The first part of the word "Ostrogoth" comes from a Germanic root *auster- meaning 'eastern'. According to the proposal of Wolfram, this was originally a boastful tribal name meaning "Goths of the rising sun", or "Goths glorified by the rising sun". By the 6th century, however, Jordanes, for example, believed that the Visigoths and Ostrogoths were two contrasting names simply meaning western and eastern Goths.