Research demonstrates that religiosity and Right-Wing Authoritarianism (RWA) are positively correlated (Altemeyer & Hunsberger, 1992). The extent to which this relationship holds across the population, however, is unknown. Because support for conformity and tradition—values fostered by religion (Saroglou, Delpierre, & Dernelle, 2004) and consonant with RWA (Altemeyer, 1996)—may be facilitated by the perception that the status quo is fair, endorsement of system-justifying beliefs should moderate the relationship between religiosity and RWA. We tested this hypothesis in a national probability sample of religiously identified New Zealanders (N = 1,600). As predicted, church attendance was associated with a steep initial increase, followed by a gradual plateau, in RWA. This relationship was, however, stronger for those who were high (vs. low) in system justification. These findings provide the first demonstration that system-justifying beliefs strengthen the relationship between religiosity and RWA, while simultaneously broadening the scope of system justification theory.