Harvard College has several types of social clubs. These are split between coeducational clubs recognized by the college, and unrecognized single-sex clubs which were subject to College sanctions in the past. The Hasty Pudding Club holds claim as the oldest collegiate social club in America, tracing its roots back to 1770. The next oldest institutions, dating to 1791, are the traditionally all-male final clubs. Fraternities were prominent in the late 19th century as well, until their initial expulsions and then eventual resurrection off Harvard's campus in the 1990s. From 1991 onwards, all-female final clubs as well as sororities began to appear. Between 1984 and 2018, no social organizations were recognized by the school due to the clubs' refusal to become coeducational.
Beginning with the Spee Club in 2015, a number of formerly single-sex organizations began to admit new members of both sexes. In 2016, Harvard announced sanctions on members of remaining single-sex clubs, aiming to push them to become coed. On September 8, 2018, Harvard announced that it would recognize an initial list of fifteen social organizations that either already were coeducational or had committed to becoming such. On June 30, 2020, Harvard announced that it would drop its social group sanctions as a result of a Supreme Court decision on sex discrimination.
