The Dreta was attested in written sources in 1243 as super fluvio Driete (and as pey der Driet in 1340, Driete in 1430, and Trijet in 1524). The origin of the name is uncertain, but is likely connected with the Croatian hydronym Dretulja and the Slovak hydronym and place name Drietoma. It may be derived from the Indo-European root *dreu̯- 'to flow'.[2]