Past research on sanctification has focused on the direct association between domain sanctification and domain satisfaction. This registered-report study focused on the predicted moderating function of sexual sanctification on the association between sexual and relationship satisfaction. An Internet panel sample of 740 women and 872 men, all married Jewish individuals residing in Israel, assessed the levels of their sexual and marital satisfaction, sexual sanctification, religiousness, and social desirability via an anonymous online questionnaire. As expected, sexual and marital satisfaction were highly correlated. As predicted, sexual sanctification was found to moderate the association between sexual and marital satisfaction for women even after controlling for age, religiousness, and social desirability. However, although the positive association between sexual and relationship satisfaction was predicted to be larger at higher levels of sanctification than at lower levels, the moderation analysis revealed a reverse pattern. In addition, the moderation effect was significant for men only after controlling for religiousness. Post hoc analyses for moderated moderation confirmed significant gender differences in the moderation function of sexual sanctification. The importance of examining gender differences in future sanctification studies and the theoretical implications for the independence of sanctification from religiousness is discussed.