In late April each year, Principia College's Parents' Weekend welcomes family members and friends to observe students living, working, and playing in their campus environment. Visitors attend classes, participate in outdoor field studies, bird walks, metaphysical talks, study abroad slide shows, and panel presentations by the administration. Visitors may also attend presentations on the Solar Car, the Wooly Mammoth dig, and other campus activities of current interest. In recent years there has been a musical concert and an evening lecture by a notable speaker.

The grand finale of Parents' Weekend is a variety show featuring a broad array of student talents. Following the variety show, the whole campus is invited to wind down at an ice cream social with live Dixieland music in Howard Center Dining Room. Everyone — students, visitors, faculty, and administrators -- enjoys sharing the campus during Parents' Weekend.