According to E. Rossoni, Tarquino derives from the Latin personal name Tarquinius, associated with the ancient Etruscan dynasty of the Tarquins, to which historical figures such as Tarquinius Priscus and Tarquinius Superbus, kings of Rome in the archaic period, belonged. Rossoni stresses that this is a learned onomastic formation, neither popular nor dialectal, which explains its scarce diffusion and the absence of large defined regional nuclei in Italy.

From the etymological point of view, the name Tarquinius is linked to an Etruscan root (possibly Tarchna or Tarchuna), whose ultimate interpretation is not entirely certain, but which became firmly associated with the Roman historical tradition. Unlike surnames born of trades, physical nicknames or place names, Tarquino belongs to the reduced group of surnames that preserve a direct historical-literary referent.

This kind of surname tends to become fixed late, often through the survival of the given name in certain family spheres, or through its reuse in humanist and learned contexts, especially from the Renaissance onwards, when the names of classical Antiquity came to be valued again.

Variants

Among the related variants stand out:

• Tarquini: a patronymic form in -ini, typical of central and northern Italy, interpreted as "the descendants of Tarquino / Tarquinio". It is the variant that reached the greatest diffusion.
• Tarquinio: a form closer to the original Latin name, documented both as a given name and as a surname.
• Tarquino: a singular and rarer form, of a learned and conservative character.