The name of the Goths is one of the most discussed topics in Germanic philology. It is first recorded by Greco-Roman writers in the 3rd century AD, although names that are probably related appear earlier. Derived from Proto-Germanic *Gutōz ~ *Gutaniz, it is closely related to and probably means the same as the names of both the Geats of southern Sweden and Gutes of Gotland. The implications of these similarities, and the actual meaning of the Gothic name, are disputed in scholarship.

In the Gothic language, the Goths referred to themselves collectively as the *Gut-þiuda "Gothic people", attested as dative singular Gutþiudai. Gutthiuda could also mean "Land of the Gothic people".

The name of the Goths was probably first recorded by Greek and Roman writers as Gutones, an exonym referring to a people dwelling in the Vistula region during the 1st–2nd century AD. Gradually, forms written with "o" instead of "u", and "th" instead of simple "t", came to dominate in both Latin (e.g. Gothi) and Greek (γόθοι). Within medieval Germanic languages, the Goths are attested as Gotan (plural) in Old English and as Goti (singular) in Old Norse.

A Germanic an-stem variant of the name, *Gutan- (Goth), is inferred from a genitive plural form gutani, found on the Pietroassa inscription and possibly equivalent to Biblical Gothic Gutanē, and from the aforementioned Germano-Latin form Gutones ~ Gotones.

Another group of related ethnonyms is believed to be attested in Scandinavia, where the oldest forms of the name of the Geats were built from a root Gaut-. This could be an ablaut form of Gut-, although it has also been proposed that this was the normal stem corresponding to *Gutans, despite the different vowel.

The Proto-Germanic form of Goth is reconstructed as *Gutaz (pl. *Gutōz), which subsequently developed into Old English Gotan. The form *Gutaz was also borrowed into Proto-Baltic as *Gudaz, attested in the Old Prussian prefix gud- (in place names) and in the Lithuanian ethnonym Gùdas, meaning 'Polish' or 'Belarusian', here transferred to the peoples that supplanted the Goths south of their territory. These forms are identical to the reconstructed Proto-Germanic name of the Gutes (Old Norse pl. Gutar ~ Gotar < *Gutōz), a North Germanic tribe inhabiting the island of Gotland. Scholars have noted that Old Norse sources do not distinguish between Gutes and Goths.

It co-existed with an an-stem variant *Gutō(n) (pl. *Gutaniz) observable in such forms as Gutones and gutani. The adjective gutniskr ~ gotniskr ('Gothic, Gutnish'), derived from an earlier *gutan-iskaʀ, along with the noun gutnar ~ gotnar ('men'), from an earlier *gutaniz, also give evidence of this an-stem formation.

The ethnonym Geats (or Gauts; Old Norse gautar) stems from Proto-Germanic *Gautōz (sg. *Gautaz), which shares the same etymology and possibly the same meaning as *Gutōz ~ *Gutaniz. The root gaut- is also preserved in several Swedish toponyms, such as the river Göta älv and the region Götaland (homeland of the Geats/Gauts), as well as in the mythic progenitor *Gaut (PGmc *Gautaz), attested by Jordanes as Gapt, whom he presents as an ancestor of the Goths. The root gut- may also be reflected in Guthalus, a river of Germania mentioned by Pliny the Elder, possibly meaning 'Gothic river'.