The gens Decimia was a plebeian family at Rome. Members of this gens are first mentioned towards the end of the third century BC.
The Decimii appear to have been originally a Samnite family of Bovianum; at least, the first of the name belonged to that place, and the others who occur in history were probably his descendants, who after obtaining the Roman franchise settled at Rome. The name itself is a patronymic surname, formed from the praenomen Decimus. In this respect it may be regarded as a Latin name, although the ancestor of the family may himself have been of Samnite extraction. The Oscan equivalent of Decimus is Dekis or Decius. It gave rise to the Roman gens Decia, which is thus a cognate of Decimius.
The Decimii used the praenomina Numerius, Gaius, Marcus, and Lucius.
The only cognomen among the Decimii is Flavus, meaning "golden" or "golden-brown."
This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "". Dictionary of Greek and Roman Biography and Mythology.