Older classifications such as the Cronquist system placed the Violaceae in an order named after it, the Violales or the Parietales.

Though the best-known genus, Viola, is herbaceous, most species are shrubs, lianas or small trees.

[16] With the establishment of higher suprafamiliar orders, which he called "Alliances", Lindley (1853) placed his Violaceae within the Violales.

[18] Historically, Violaceae has been placed within a number of orders since Lindley's treatment, principally Violales (Hutchinson, Takhtajan, Cronquist, Thorne) and the equivalent Parietales (Bentham and Hooker, Engler and Prantl, Melchior),[19] although such placement was considered unsatisfactory,[4] but also Polygalinae (Hallier) and Guttiferales (Bessey).

[4] Molecular phylogenetics resulted in the Angiosperm Phylogeny Group (APG) places it as one of a large number of families within the eudicot order Malpighiales.

[23][3][24] Oxalidales (outgroup) Euphorbiaceae Peraceae Picrodendraceae Phyllanthaceae Linaceae Ixonanthaceae Salicaceae Scyphostegiaceae Samydaceae Lacistemataceae Passifloraceae Turneraceae Malesherbiaceae Violaceae Goupiaceae Achariaceae Humiriaceae Hypericaceae Podostemaceae Calophyllaceae Clusiaceae Bonnetiaceae Ochnaceae Quiinaceae Medusagynaceae Rhizophoraceae Erythroxylaceae Ctenolophonaceae Pandaceae Irvingiaceae Chrysobalanaceae Euphroniaceae Dichapetalaceae Trigoniaceae Balanopaceae Malpighiaceae Elatinaceae Centroplacaceae Caryocaraceae Putranjivaceae Lophopyxidaceae The Violaceae are a medium-sized family with about 22–28 genera, and about 1,000–1,100 species.

[3][25][22][4] Many attempts have been made at an intrafamilial classification, but these have largely been artificial, based on floral characteristics.

Early classifications identified two major divisions, that were followed by most taxonomists;[15][17] These also had biogeographical correlation, with the latter being almost exclusively South American and African, and the former being distributed in Europe in addition to the Americas.

[27][3] About 600 species, in the following genera, but mainly in Viola and Hybanthus and including all four of the lianescent genera in the family (Agatea, Anchietea, Calyptrion and Hybanthopsis;[28] Molecular phylogenetic studies have revealed that many of these divisions were not monophyletic, partly due to homoplasy.

[3] The molecularly defined subdivisions are;[3] In Clade 1, Schweiggeria and Noisettia are monotypic and form a sister group to Viola.

The Violaceae have an overall cosmopolitan distribution,[3] but are essentially tropical and subtropical, with the exception of the numerous Northern Hemisphere temperate species of Viola, the largest genus, which is also occurs at higher altitudes in its tropical and subtropical regions, where the shrub, tree and lianescent species are concentrated.