A bifolium is a type of mathematical curve. It can also refer to:
Animals A genus of brachiopods
Plants Orchid genera now considered synonyms of Neottia Bifolium Petiver ex Nieuwland Bifolium P. G. Gaertner, B. Meyer et J. Scherbius Bifolium cordatum, a synonym of Maianthemum bifolium A taxonomic section of the genus Larrea
Manuscripts A single sheet of parchment constituting two folios