Mission is central to social venturing, but little is known about the nature and origins of social venture mission. The field lacks a theoretical framework for understanding the moral content of “prosocial” missions that rely on quite different—and potentially conflicting—moral values. We engage in an exploratory quantitative study, wherein we draw on moral foundations theory and social identity theory to develop framing questions related to the moral discourse in social venture missions and the role of founders’ partisan identities in infusing these missions with moral values. We construct a novel dataset by performing computer-aided text analysis on the mission statements of over 50,000 nascent nonprofit ventures in the United States and matching founding team members to voter registration data. We find that moral foundations are frequently espoused in mission statements. We also find that the partisan political identity of the founding team is strongly associated with differences in the moral discourse in social ventures’ stated missions in ways that intriguingly differ from prior work relating moral foundations to political beliefs. Our work contributes to social entrepreneurship research by offering a new way of looking at social venture mission, a road map for future empirical studies, and practical and policy implications.