Allenanthus was a genus of flowering plants in the family Rubiaceae but is no longer recognized.

[1] Allenanthus was named by Paul Standley in 1940 in Annals of the Missouri Botanical Garden.

Until 2004, two species had been recognized, but fieldwork has shown that there is a continuum of variation between them.

[3] Comparisons of morphological characters and DNA sequences have shown that Allenanthus is embedded in Machaonia.

[1] Because of these results, Allenanthus is no longer maintained as a separate genus.