Agency, a behavioral and psychological concept, is an individual’s sense of what they can do and what they think they can do. It is imperative to understand how a sense of agency in youths can be fostered and transformed into constructive action. This study builds on previous research to better identify predictors of agency, focusing on social and political involvement and opportunity structure. Additionally, it analyzes and proposes the use of a new measure of agency, the Community Leadership (CL) scale. Eighty-five teens (ages 13 to 18) were administered surveys. Involvement was found to be significantly related to agency. It was also related to opportunity structure, but opportunity structure was not significantly related to agency. Opportunity structure seems to partly influence the relationship between involvement and agency. When compared to previously validated measures of agency, the CL scale proved to be a shorter and psychometrically sound alternative measure.