Howard Taylor Ricketts (February 9, 1871 – May 3, 1910) was an American pathologist after whom the family Rickettsiaceae and the order Rickettsiales are named. He was born in Findlay, Ohio. In the early part of his career, Ricketts undertook research at Northwestern University on blastomycosis. He later worked in the Bitterroot Valley of Montana and at the University of Chicago on Rocky Mountain spotted fever. This early pathology, entomology and epidemiology research in Hamilton, Montana lead to the eventual formation of the Rocky Mountain Laboratory there.