John Martin Keith (June 5, 1859 – July 8, 1929) was a clerk and banker who was the only person to serve three nonconsecutive terms as mayor of Missoula, Montana.

Keith was born in rural New Brunswick, British North America on June 5, 1859, where he was raised on a farm and educated in the local public school system.

His home, the John M. Keith House is on the National Register of Historic Places listings in Missoula County, Montana.

A low-pitched hipped roof and widely overhanging eaves augment the horizontal emphasis characteristic of the style, which is further enhanced by terra cotta tiles capping hip-roofed chimneys.

Much of the first-floor interior retains its original opulence, strongly influenced by the Craftsman style of the period, including exquisite woodwork, elegant paneling, pocket sliding doors, and a copper-clad entry hall fireplace.