The Tuscan order is one of the two classical orders developed by the Etruscans, the other being the composite order. It is influenced by the Doric order, but with un-fluted columns and a simpler entablature with no triglyphs or guttae. While relatively simple columns with round capitals had been part of the vernacular architecture of Italy and much of Europe since at least Etruscan architecture, the Romans did not consider this style to be a distinct architectural order. Its classification as a separate formal order is first mentioned in Isidore of Seville's Etymologies and refined during the Italian Renaissance.

The Composite order is a mixed order, combining the volutes of the Ionic order capital with the acanthus leaves of the Corinthian order. In many versions the composite order volutes are larger, however, and there is generally some ornament placed centrally between the volutes. The column of the composite order is typically ten diameters high, though as with all the orders these details may be adjusted by the architect for particular buildings. The Composite order is essentially treated as Corinthian except for the capital, with no consistent differences to that above or below the capital.