William Starling Sullivant (January 15, 1803 – April 30, 1873) was an early American botanist recognized as the foremost authority on bryophytes in the United States.

Sullivant collected plants throughout the Ohio region and built up a large herbarium with an emphasis on grasses and sedges.

He presented his findings in a bound two-volume folio, Musci Alleghaniensis (1845,1846), containing dried specimens of the mosses he had collected along with accompanying text in Latin for each species.

[3] Sullivant's contribution was later published separately under the title, The Musci and Hepaticae of the United States, east of the Mississippi River (1856).

[4] In 1864 Sullivant published his most important work, Icones Muscorum, containing 129 illustrations and descriptions of the mosses indigenous to eastern North America.

[2] During his career Sullivant had named and described 270 species of bryophytes and had gained worldwide recognition as the preeminent authority on North America mosses and related plants.