Established in 1918 by Missouri two-year college presidents, Phi Theta Kappa is the largest honor society in American higher education with more than 1.3 million members and 1100 chapters located in 50 states, U.S. territories, Canada, Germany, and Japan. In 1929, the American Association of Community Colleges recognized Phi Theta Kappa as the official honor society for two-year colleges and in 2000 the Association of College Honor Societies recognized Phi Theta Kappa as the general scholarship honor society serving associate degree granting institutions. At the time of its founding, Phi Theta Kappa was patterned after the prestigious senior college honor society Phi Beta Kappa. Thus, membership was conferred at graduation and few programs and services were offered to members.

The explosive growth of community colleges in the 1960s led Phi Theta Kappa to expand its mission to reflect the nurturing philosophy of the institutions it served. Students were inducted as freshmen and study programs were offered. The complement of services, innovative programs, and membership benefits offered by Phi Theta Kappa today are unequaled among honor societies. The programs offered focus upon the Society's Hallmark of Scholarship, Leadership, Service and Fellowship. It is estimated that 200,000 students participate in Phi Theta Kappa programs each year.

Annually, more than 82,000 students are inducted into Phi Theta Kappa. To be eligible for membership generally a student must complete a minimum of twelve hours of associate degree course work and earn a grade point average of 3.5 or higher. Students must maintain a high academic standing throughout their enrollment in the two-year college, generally a 3.25 GPA. The average age of a new member is 29, ranging from 18 to 80. Part-time and full-time students are eligible for membership. Students pay a one-time membership fee of $55. Chapters and regional organizations may also assess dues.