Unlike many other schools, Greyson does not host local branches of national fraternities or sororities - the university charter officially prohibits any interference in the Greek system on the part of outside groups. Instead, the fraternities and sororities in Shadowgard are run by the students themselves, usually with the (occasionally strongly worded) guidance of alumni, and funded through alumni donations and student membership fees. The wealthier and more influential groups occupy the ten houses on Fraternitas Drive, while, with only one notable exception (in the form of Gamma Lambda Mu/Phi), the other groups meet in public spaces and their members live in the dorms like any other students. It's easy enough to establish a new fraternity or sorority, all things considered; it's harder to keep that fraternity viable and build enough influence to sway the governing Greek Council and so forth. Five different Greek organizations have been formed and dissolved within the last seven years, and this track record only serves to keep most potential pledges away from new organizations, contributing to the cycle of failure. In general, the Greek organizations do not hold much sway over the general student body - only twelve to fourteen percent of all undergraduate students actively participate in Greek life, and the university is careful to curb their overall power and influence. Greek life is central to the college experience of a select few, and largely invisible to those who would rather ignore it.

Greek life at Greyson is administered by the office of the Dean of Students and the student-run Greyson Greek Council, which is composed of a single representative from each active fraternity and sorority currently recognized by the university, as well as five unaffiliated students elected by the general student body. The Council oversees all Greek affairs, including revisions to the relevant passages of the university and student charters, disciplinary action toward individual groups or their members, and approval of new groups, though all decisions can be overturned by the Dean of Students unless the Council has at least a three-quarters majority. The Student Senate also shares some oversight of the Greek Council, particularly where revisions to the student charter are concerned.

The current fraternities and sororities at Greyson are as follows: