James McClellan Hamilton (October 1, 1861 – September 23, 1940) was an American historian and economist who was the third president of Montana State University.

His Presbyterian paternal grandparents emigrated to the United States from Belfast, Ireland, shortly after the American Revolutionary War.

His father died when he was 14 years old, and James began working during the spring, summer, and fall in order to support his family.

But listening to the debates there convinced him that multiple campuses would be more likely to win legislative approval in Montana's bitter political climate (in which towns and cities lobbied hard to undercut one another in an attempt to reap state largesse).

[4] While serving on the board, Hamilton chose the sites (Missoula and Bozeman) for the two state colleges, their first presidents, and their first faculty members.

The first president, Augustus M. Ryon, had only served for a year before coming into significant conflict with faculty and local businesspeople who disagreed with his intent to build a technology-oriented engineering school.

Reid was determined, however, to stop students from dancing, drinking, gambling, playing cards, and soliciting prostitutes (common distractions in a frontier town like Bozeman), and his constant anti-vice campaign took a significant toll on his health.

He was friendly and outgoing, which made him popular among state legislators, local Bozemanites, and students, but he was also a decisive leader who rarely deviated from a course of action (once decided upon).

[6] Determined to make the college into a school of technology, Hamilton rapidly expanded the curriculum in areas such as biology, chemistry, engineering, geology, and physics.

Further marking this change in direction, the school was officially renamed the Montana College of Agriculture and Mechanic Arts in 1913 (although that name was in widespread use as early as 1894).

[4] The giant whitewashed "M" on the side of the Mount Baldy in the foothills of the Bridger Range was first built in 1916, and in 1917 ROTC came to campus for the first time.

[8] In 1957, Florence Hamilton asked Dr. Merrill G. Burlingame, a professor of history at Montana State College, to edit the latter manuscript into a book.

His funeral was held in what is now Romney Gym, attended by all the faculty and students of Montana State College as well as many members of the public.

That same day, he was elected the first president of the newly formed "Quarter Century Club" (an association of college faculty and staff with twenty-five years or more of service).

[8] In 2011, three historians who wrote a history of MSU were asked to name Montana State University's most important presidents.

Pierce Mullen, Robert Rydell, and Jeffrey Safford named Hamilton one of the four top presidents in the university's history.

Hamilton, the scholars said, turned Montana State from an ill-defined, small school into a large agricultural college with a strong but narrow focus.