Alpha Gamma Sigma (ΑΓΣ; commonly known as AgSig or AGS) is a national collegiate social and professional agricultural fraternity in the United States.

[1][2] Alpha Gamma Sigma began as a local agricultural fraternity at University of Missouri, on January 28, 1923.

[1][3] A similar organization called the National Agriculture Club formed at Ohio State University on October 23, 1922; its name was changed to Tau Gamma Phi fraternity during its first year.

[3] There, the fraternity adopted a revised constitution and by-laws, a member's badge and pledge pin, a crest, colors, a flower, a motto, and a ritual.

[6] Its current motto is "Preparing Men for Life by Coming together as Scholars, Living as Brothers, Becoming Leaders of Tomorrow".

[3][2] The mission statement of Alpha Gamma Sigma is "Preparing men for life by coming together as scholars, living as brothers, becoming leaders of tomorrow.