Paid employment is one of the most common extracurricular activities among full-time undergraduates, and an array of studies has attempted to measure its impact. Methodological concerns with the extant literature, however, make it difficult to draw reliable conclusions. Furthermore, the research on working college students has little to say about relationships between employment and leadership development, a key student learning outcome. This study addressed these gaps in two ways, using a national sample of 77,489 students from the 2015 Multi-Institutional Study of Leadership. First, it employed quasi-experimental methods and hierarchical linear modeling (HLM) to investigate relationships between work variables (i.e., working status, work location, and hours worked) and both capacity and self-efficacy for leadership. Work location for students employed on-campus was disaggregated into 14 functional departments to allow for more nuanced analysis. Second, this study used text mining methods to examine the language that participants used to define leadership, which enabled a rich comparison between students' conceptualizations and contemporary leadership theory. Results from HLM analysis suggested that working for pay is associated with lower self-reported leadership capacity, as defined by the social change model of leadership development, and that this relationship varies by workplace location and across institutional characteristics. The association between working status and self-efficacy for leadership was found to be practically non-significant, and hours worked per week were unrelated to either outcome. Results from text mining analysis suggested that most students conceptualize leadership using language that resonates with the industrial paradigm of leadership theory--leadership resides in a person with authority, who enacts specific behaviors and directs a group toward a goal. Disaggregated findings suggested that students who work off-campus consider leadership differently, using language consonant with contemporary, post-industrial scholarship--leadership is a dynamic, relational, non-coercive process that results in personal growth and positive change. In sum, the findings both echo and challenge aspects of existing research on leadership and working college students. Future research should explore off-campus work environments in greater detail, while practitioners and scholars who supervise students should aim to infuse post-industrial conceptualizations into on-campus work environments. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]