William Denison Lyman (December 1, 1852 – June 21, 1920) was an author, professor, and historian.

[1] After an attempt at farming and teaching at the University of New Mexico at Santa Fe,[1] Lyman taught history and served as department head at Whitman College from 1888 until his death in 1920.

Lyman contributed published papers to the American Antiquarian Society.

Lyman climbed and documented many peaks in the Pacific Northwest.

[1][3] Lyman House at Whitman College is named in his honor,[4] as are the Lyman Glaciers on Mount Adams[3] and in the North Cascades.