Background: This study investigates how dyadic coping interacts with gender identity and within-couple gender ideology (dis)similarity to influence marital satisfaction in 202 heterosexual married couples with mild cognitive impairment (MCI). Research Design: We utilized cross-sectional dyadic data and actor–partner interdependence moderation models to examine the interactions between dyadic coping, gender ideology (dis)similarity, and gender identity. Results: The results revealed positive associations between dyadic coping and marital satisfaction for both persons with mild cognitive impairment (PwMCIs) and their spouse care partners (SCPs). Two-way interactions indicated that: (1) the association between a SCP’s dyadic coping and their own marital satisfaction was moderated by the couple’s gender composition; and (2) the association between a PwMCI’s dyadic coping and their own marital satisfaction was moderated by ideological dissimilarity with their spouse. Conclusions: These findings inform culturally sensitive interventions and extend dyadic health theory in non-Western contexts.