Colby’s student center, Cotter Union, includes Page Commons (for lectures, performances, and dances), Pulver Pavilion, the bookstore, the student post office, and the Office of Campus Life. The Pugh Center contains offices for multicultural organizations and meeting space for social and cultural programs. The Joseph Family Spa, a snack bar, is in Pulver Pavilion, and the Marchese Blue Light Pub is upstairs.

Opened in 1985, renovated and expanded in 2007-08, Cotter is the center of social life on campus, where students meet and hang out. There is a large-screen television and an information desk in Pulver Pavilion, which is a crossroads for pedestrian traffic on campus.