The current Student Association was formed in 1921. Interest in forming a student government dates from 1914. At that time, President Milne rejected a student petition to form a student government commenting, "There is no place in this institution for the association and activities contemplated in this petition". President A.R. Brubacher(1915-1939) took a more favorable attitude toward student government. In response to a 1915 student petition, he instructed Professor Risley to form a committee to study the possibility of creating a student government. There appears to have been an attempt at forming a rudimentary student organization in January, 1916. As a result of Risley's study, Myskania was formed in 1917. Myskania, referred to in their 1917 constitution as the student council, was an honorary body consisting entirely of seniors who were to represent "the opinion and to improve the department of the student body." Myskania, in turn, created the Student Association in 1921. The general business of running student funded activities such as the yearbook and the student newspaper appears to have been the concern of the Student Assembly. The new Student Association appears to have carried on the responsibilities of the Student Assembly. (For a history of Myskania, see the Myskania finding aid.)

The Student Association's original purpose as stated in its 1921 constitution, was "the management of all matters of student interest not academic in nature." The Student Association controlled the legislative, financial and executive powers of the government, while Myskania acted as a single judicial branch and as guardian of school traditions. According to the 1921 constitution, the executive duties of the S.A. fell on the executive board made up of the president, the vice president, the secretary and the treasurer. The Executive Board's duty was to carry out the provisions of the Assembly and act as a court of appeals. By 1928, a new constitution for the Student Association changed the executive branch. Instead of the Executive Board, the executive branch was run by Student Council, different from the original student council (Myskania), which was made up of the president, the vice president, the secretary, and the presidents of the four classes. The new Student Council had broader duties than the Executive Board including: arranging the program for Student Association meetings, providing for the publication of the student directory, charter all boards, committees and associations by securing support from the Student Association through the budget and executing all legislation passed by the Student Association.

In the 1930's and 40's Student Association assemblies dealt with contemporary issues such as the presidential campaigns, the New Deal, and World War II. In 1949 the Student Association was involved in a project called CARE, an organization to help the children of the war. From the end of the 1960's the Student Association has placed increasing emphasis on student rights and equal opportunity. Minorities began to organize themselves and form groups including the Women's Liberation Front, Black Students Alliance and Lesbians for Freedom and the Student Association gave formal recognition to these new organizations. The trend continues to this day. At the same time the Student Association supported new programs such as the Equal Opportunity Program (EOP), developed in 1973.

While continuing to sponsor equal opportunity programs for all races and creeds, the Student Association has also, in more recent years, turned its attention to the environment (NYPIRG was recognized on campus in 1982), as well as supported such academic initiatives as the Frosh Reading Program. Long term issues include opposition to ROTC, during the 1960's and 70's for its support for the United States Government's Vietnam War policy, in the 1980's because ROTC discriminated against gay and lesbian candidates; reproductive rights and the establishment of a Birth Control Center on campus. The prominent development of the 1970's through 1990's was the Student Association s new power in academic affairs--one prominent example of that was their accessing the competence of teaching faculty. The results of their surveys were distributed in the ACT and SCATE Booklets.

In the 2019-2020 academic year, the Board of Finance launched an investigation into the Student Association president for the misuse of funds and found the student guilty. At the end of the investigation, the Board of Finance additionally requested a trial in which the Student Association Senate judges ruled that the president be impeached on the basis of Article I: abuse of power and Article II: Neglect of duty.