古典主义建筑是以古典主义风格建造的建筑，是西式建筑风格的一类。广义上的古典主义建筑是指工业革命以前以建筑外立面形式为主要设计出发点的建筑。狭义上的古典主义建筑是指古希腊和古罗马时期的以柱式(Order)为主要设计出发点的建筑，和以后的其他建筑样式相区别。

Classical architecture usually denotes architecture which is more or less consciously derived from the principles of Greek and Roman architecture of classical antiquity, or sometimes even more specifically, from the works of Vitruvius. Different styles of classical architecture have arguably existed since the Carolingian Renaissance, and prominently since the Italian Renaissance. Although classical styles of architecture can vary greatly, they can in general all be said to draw on a common "vocabulary" of decorative and constructive elements. In much of the Western world, different classical architectural styles have dominated the history of architecture from the Renaissance until the second world war, though it continues to inform many architects to this day.