The 1998 APG system and the 2003 APG II system assign it to the order Santalales in the clade core eudicots. Circumscription of the family Olacaceae varies between different authorities. About 28 genera are accepted in the family, out of which a total of 15 by the Germplasm Resources Information Network. However, the circumscription of the family are still under investigation and some authors split the family into smaller entities. The formal reconfiguration of this family (as well as the rest of the order Santalales) proposed by Nickrent and co-workers, has not been recognised by the APG III-system of 2009.
- Olacaceae sensu stricto
- Dulacia - 13 species of South America
- Olax - ca 40 species of the Old World tropics
- Ptychopetalum - 2 species of tropical South America and 2 species of western and central Africa
- Anacolosa - 16 species of the Old World tropics
- Aptandra - 3 species in tropical America and 1 species in Africa
- Cathedra - 5 species of South America
- Chaunochiton - 3 species of tropical America
- Harmandia - one species in southeastern Asia
- Hondurodendron - one species in Honduras
- Ongokea - one species in Africa
- Phanerodiscus - 3 species of Madagascar
- Curupira - one species in Amazonian Brazil
- Douradoa - one species in Brazil
- Malania - one species in China
- Ximenia - 10 species of the Old and New World tropics
- Coula - one species in tropical western Africa
- Minquartia - one species in tropical America
- Ochanostachys - one species in western Malaysia
- Diogoa - 2 species of tropical Africa
- Engomegoma - one species of tropical Africa
- Scorodocarpus - one species in Malaysia
- Strombosia - 3 species of tropical Asia and 6 species of tropical Africa
- Strombosiopsis - 3 species of tropical Africa
- Tetrastylidium - 2 species of South America
- Erythropalum - one species of Indomalaysia
- Heisteria - ca 33 species of tropical America and 3 species in Africa
- Maburea - one species in Guyana
- Octoknema - 14 species of tropical Africa
- Excluded or unplaced genera
- Brachynema - morphological cladistic analysis places this genus in Ericales, and no genetic study has yet been published
- Schoepfia - excluded and combined with Arjona and Quinchamalium (previously Santalaceae) as the family Schoepfiaceae
- Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2013–07–06.
- Valéry Malécot and Daniel L. Nickrent. 2008. "Molecular Phylogenetic Relationships of Olacaceae and Related Santalales". Systematic Botany 33(1):97-106.
- Nickrent DL, Malécot V, Vidal-Russell R & Der J (2010) A revised classification of Santalales. Taxon 59(2): 538-558.
- Malécot V, Nickrent DL, Baas P, van den Oever L, Lobreau-Callen D (2004) A morphological cladistic analysis of Olacaceae. Syst. Bot. 29(3): 569-586.