Renn Fayre is an annual three-day celebration at Reed with a different theme each year. Born in the early 1970s as an actual renaissance fair, it has long since lost all connection to anachronism and the Renaissance, although its name has proven invincible.

Renn Fayre commences with Thesis Parade, where graduating seniors make a symbolic march to deliver their theses to the registrar. The Fayre runs from Friday to Sunday, beginning on the last day of classes for the spring semester. The week after Renn Fayre is Reading Week, in which no classes are held; final examinations are held in the following week.

Renn Fayre is often called the metaphorical "explosion" of the student body after a year of intense pressure. Traditions include bizarre art installations, insect-eating contests, occasional motorized couches, naked people painting themselves blue (a vague tribute to the ancient Picts), a Beer Garden, the Glow Opera (performed at night by actors in lightstick-covered suits) and a general sense of mayhem, often fueled by drugs and alcohol. Serious injuries are rare, thanks in part to the presence of vigilant student volunteers (known as "Karma Patrol" and "Border Patrol", who ensure guest wellness and the exclusion of unauthorized visitors respectively) and the non-profit White Bird Clinic [1] .

Student participation is essentially unanimous, and even faculty and staff attend some of the festivities. Alumni and authorized guests may also participate.