E. Rossoni proposes that the surname derives from a name compounded from Iorio —an archaic, contracted form of Giorgio— and Johannes. Its fixing as a surname is documented in the figure of Antonio Giuranno, a Venetian purveyor of the early 16th century active in the Salento area —that is, the southernmost zone of the region of Puglia, in southern Italy. Rossoni places the surname Giuranna in Nardò, Gallipoli and Galatone, all in the Lecce area; he notes that Giuranni, practically unique, would answer to an incorrect transcription of the former, and that Giuranno also appears in the Lecce area, specifically in Tuglie and Taviano.

V. Blunda, by contrast, proposes an independent origin of a different nature for the Sicilian form of the surname. According to Blunda, it comes from the dialect word ggiuràna, meaning "frog", and would have arisen as a nickname applied to a person with a shrill, insistent voice, likened to the croaking of the amphibian —a frequent motivation in Sicilian surnames with a zoonymic base. It may also have alluded to someone who lived near wetlands where frogs were abundant.

Both proposals point to independent origins: an onomastic etymology in Apulia and a zoonymic dialect etymology in Sicily, which suggests that the surname has multiple independent clusters of origin (ceppi).