Many of the members of the order are parasitic plants, mostly hemiparasites, able to produce sugars through photosynthesis, but tapping the stems or roots of other plants to obtain water and minerals; some (e.g. Arceuthobium) are obligate parasites, have low concentrations of chlorophyll within their shoots (1/5 to 1/10 of that found in their host's foliage), and derive the majority of their sustenance from their hosts' vascular tissues (water, micro- and macronutrients, and sucrose).

[2] As in the earlier APG III system, it was accepted that Olacaceae sensu lato was paraphyletic but new family limits were not proposed as relationships were considered uncertain.

[3][2] As of July 2021[update], this seven-family division of the Santalales was explicitly accepted by the World Flora Online,[1] and implicitly by Plants of the World Online, in that it accepted none of the extra families recognized by other sources.

[5] As of July 2021[update], the Angiosperm Phylogeny Website accepted the families resulting from the division of Olacaceae s.l.

[4] In the classification system of Dahlgren, the Santalales were in the superorder Santaliflorae (also called Santalanae).