This article conceptually links theory and research on volunteerism to different forms of political activity, specifically activism and civic engagement. Multiple perspectives and measures of personality as antecedents of volunteerism, activism, and civic engagement are outlined, including individual differences in motivations, interpersonal orientations, and traits. Next, self-report data from 624 people involved in AIDS service organizations (as clients, volunteers, staff, or supporters) are utilized to empirically explore the best personality predictors of AIDS activism and civic engagement. Other-focused rather than self-focused motivation better predicted AIDS activism and civic engagement. The only measure of interpersonal orientation consistently related to these outcomes was communal orientation; as well, only the trait of extraversion was related to both outcomes. In analyses testing the predictive power of constellations of personality measures, other-focused motivation better predicted AIDS activism and civic engagement than the other measures of motivation, interpersonal orientation, and traits. Finally, meditational analyses supported a developmental sequence in which other-focused motivation leads to specific activism, which, in turn, encourages broader civic engagement. The discussion focuses on theoretical implications for understanding the impact of personality on different forms of citizenship behaviors and of the applicability of the Volunteer Process Model for studying political activity and civic engagement.