Harrison Gray Dyar Jr.

Harrison Gray Dyar Jr.
Born	(1866-02-14)February 14, 1866 New York City, U.S.
Died	January 21, 1929(1929-01-21) (aged 62) Washington, D.C., U.S.
Nationality	American
Citizenship	United States
Alma mater	Massachusetts Institute of Technology (B.S.) Columbia University (M.A.) Columbia University (Ph.D.)
Years active	1889–1929
Known for	Scientist, entomologist
Parent(s)	Harrison Gray Dyar, Eleonora Rosella Hunt
Relatives	Harrison Gray Otis (second cousin)

Harrison Gray Dyar Jr. (February 14, 1866 – January 21, 1929) was an American entomologist. Dyar's Law, a pattern of geometric progression in the growth of insect parts, is named after him. He was also noted for eccentric pursuits which included digging tunnels under his home. He had a complicated personal life and along with his second wife he adopted the Baháʼí Faith.