This study combines critical service learning (Mitchell, 2008) and antioppressive pedagogies (Kumashiro, 2002) to highlight the importance of using community sites aimed toward transformational social change. How sites are structured and how students are positioned influence what students learn from the experience. Using ethnographic methods, I analyze experiences of college service learners working with a labor union to illustrate how activist-oriented organizations are fundamental to providing critical spaces of learning and social change.