Dendrobium section Rhizobium is a section of the genus Dendrobium.
Plants in this section have thick, fleshy to terete leaves produced along a thin and wiry stem.
The section was established in 1851 by John Lindley and Joseph Paxton. Species in this section was included in the genus Dockrilla, named after Alick Dockrill, by authors including David Jones, Mark Clements and Stephan Rauschert for some species formerly included in the genus Dendrobium. A 2008 paper, based on a study the molecular phylogenetics of a wide range of related orchids, concluded that "the splitting of Australasian dendrobiums into various genera by other authors is excessive and unnecessary" moving the species back to the section Rhizobium.
Plants from this section are found in Australia, New Guinea, New Caledonia and Vanuatu.
Dendrobium section Rhizobium comprises the following species: