The Ionic order was also formed during the Archaic period and its use spread from Ionia -where it appeared for the first time- to the Cyclades, Attica and to a part of Macedon, whereas it was particularly used in the Greek west. It mainly differs from the Doric order in the form of the column and the arrangement of the entablature. A crepis of usually three steps also exists, with a slight moulding in their lower part. However, the column is not direcly based on the stylobate, but on a round foundation called the spira. This base is separated into two parts, the concave, which is called scotia, and the convex one, which is called torus or kymation. Some times (in Minor Asia mainly) this base was placed on a square slab, the plinth.

Whereas the Doric column is a purely Greek creation, the Ionic one apparently assumed foreign elements and adapted them. The earliest Ionic columns also lead to that conclusion; they have been found in Lesbos and Troas, and thus are called Aeolic. The Aeolic columns have two volutes, among which a palmette is developed, and at their base there usually is a floral pattern.

The differences between Ionic and Doric order are also apparent in the architrave, which is not unified, but is divided into three successive and protruded mutule. In Ionia, over the architrave we meet a decorative area with a Lesbian kyma and supports of the cornice, which are called dentils. On the islands and Attica the use of the frieze with relief and sometimes painted representations prevailed.

The architectonic design of Ionic temples does not differ greatly from that of the Doric. However, the Ionic temples are as a rule a lot larger in size. Their facade usually has 8 columns, the height of which could reach 19 metres (Heraion and Samos). In Ionia the magnificent dipteral type is preferred, whereas on the islands, in Attica and in Delphi distyle in antis and the four-column is adopted, which are more appropriate for smaller temples and treasuries.