The given name Eric, Erich, Erikk, Erik, Erick, or Eirik is derived from the Old Norse name Eiríkr [ˈɛiˌriːkz̠] (or Eríkr [ˈeˌriːkz̠] in Old East Norse due to monophthongization).

The first element, ei- may be derived from the older Proto-Norse *aina(z), meaning "one, alone, unique", as in the form Æ∆inrikr explicitly, but it could also be from *aiwa(z) "everlasting, eternity", as in the Gothic form Euric. The second element -ríkr stems either from Proto-Germanic *ríks "king, ruler" (cf. Gothic reiks) or the therefrom derived *ríkijaz "kingly, powerful, rich, prince"; from the common Proto-Indo-European root *h₃rḗǵs. The name is thus usually taken to mean "sole ruler, autocrat" or "eternal ruler, ever powerful". Eric used in the sense of a proper noun meaning "one ruler" may be the origin of Eriksgata, and if so it would have meant "one ruler's journey". The tour was the medieval Swedish king's journey, when newly elected, to seek the acceptance of peripheral provinces.

Eric is one of the most commonly used Germanic names in the United States, along with Robert, William, Edward and others.

The most common spelling across Fennoscandia and in the Netherlands is Erik. In Norway, another form of the name (which has kept the Old Norse diphthong) Eirik is also commonly used. The modern Icelandic version is Eiríkur [ˈeiːˌriːkʏr̥], while the modern Faroese version is Eirikur.

In Estonia and Finland (where Fenno-Swedish remains an official minority language), the standard Nordic name form Erik is found, but it may also be spelled phonetically as Eerik (Finnish: [ˈeːrik]), in accordance with Finnic language orthography, along with a slew of other unique Balto-Finnic variant forms including Eerikki, Eero, Erki and Erkki.

Although the name was in use in Anglo-Saxon England, its use was reinforced by Scandinavian settlers arriving before the Norman conquest of England. It was an uncommon name in England until the Middle Ages, when it gained popularity, and finally became a common name in the 19th century. This was partly because of the publishing of the novel Eric, or, Little by Little by Frederic Farrar in 1858.

The Latin form of the name is Euricus or Erīcus (Medieval Latin: [ɛˈriː.kus]), which was also adopted into Old Swedish usage (for example, cf. 15th century Kalmar Swedish historian Ericus Olai). Whence come the Greek forms Ερίκος (Eríkos) or Ερρίκος (Erríkos) (both pronounced [eˈri.kos]), in addition to the direct Nordic borrowing Έρικ (Érik).

Éric (French: [e.ʁik]) is used in French, Erico or Errico in Italian, Érico in Portuguese. (Note some phonetically simplified modern forms may be conflated with descendants of cognate name Henry via Henrīcus, Henrik, from Proto-Germanic Haimarīks, sharing the stem *rīks.)

Among Slavic languages, most using the Latin alphabet borrow Erik, but there also exists Polish Eryk. The name is adapted into Cyrillic as Russian Э́йрик (Éyrik) or Э́рик (Érik), and Ukrainian Е́рік (Érik). The Baltic languages use forms such as Latvian Ēriks and Lithuanian Erikas.

And in Germany, Eric, Erik and Erich are used. In South America, the most common spelling is Erick.

In Norway, Sweden and Finland, the name day for derivations of Erik and Eirik is 18 May, commemorating the death of Saint King Eric IX of Sweden, founder of the royal House of Eric.

The feminine derivative is Erica or Erika.