Commelinoideae is a subfamily of monocotyledonous plants in the dayflower family (Commelinaceae).

The subfamily is further broken down into two tribes, the Tradescantieae, which includes 26 genera and about 300 species, and the Commelineae, which contains 13 genera and about 350 species.

The Commelinoideae is separated morphologically from the other subfamily, Cartonematoideae, in having glandular microhairs, arteries containing needle-like calcium oxalate crystals called raphide canals in between the veins of the leaves, and flowers that are virtually never both yellow and actinomorphic.

[1] Molecular phylogenetics also supports the separation of the two subfamilies.

[2] The following is a phylogeny, or evolutionary tree, of most of the genera in Commelinoideae based on DNA sequences from the plastid gene rbcL[2] Tinantia Weldenia Thyrsanthemum Elasis Tradescantia + Gibasis Callisia + Tripogandra Amischotolype Coleotrype Cyanotis Belosynapsis Dichorisandra Siderasis Cochliostema Plowmanianthus Geogenanthus Palisota Spatholirion Commelina Pollia Polyspatha Aneilema + Rhopalephora Floscopa Stanfieldiella Buforrestia Murdannia Anthericopsis