兰目是单子叶植物纲中的一个分支，以前有将其称为“微子目” （Microspermae） 或“香草目”（Gynandrae） 的。兰目植物是一般植物学家公认的最进化的单子叶植物类群，由于现代许多学者认为单子叶植物是比双子叶植物进化更好的种类，所以兰科植物几乎可以说是最进化的植物。其种类最多，达20000多种，几乎占单子叶植物的1/4，是种子植物的第二大科，仅次于菊科。花大而鲜艳芳香，所有的特征都表现了对昆虫传粉的高度适应。

兰目包括四个科：

2003年根据植物亲缘分类的APG II 分类法，将兰科分入天门冬目，将水玉簪科分入薯蓣目，撤消兰目。

Orchidales is a botanical name of an order of flowering plants. In taxonomical systems, this is a relatively recent name as early systems used descriptive botanical names for the order containing the orchids. The Bentham & Hooker and the Engler systems had the orchids in order Microspermae while the Wettstein system treats them as order Gynandrae. Circumscription of the order will vary with the taxonomic system being used. Although mostly the order will consist of the orchids only (usually in one family only, but sometimes divided into more families, as in the Dahlgren system, see below), sometimes other families are added: