Using three-annual-wave, dyadic data from different-gender, dual-earner couples in the United States (N = 904 couples), we delineated associations between work-family conflict and housework division for husbands and wives across COVID-19 and tested the moderating role of each spouse’s traditional gender attitudes in these associations. We used the conservation of resource theory and family systems theory as guiding frameworks. Couples were from a nationally representative sample of married couples recruited using a two-stage cluster stratification strategy. Using a random-intercept, actor-partner interdependence, cross-lagged panel model, we found bidirectional, longitudinal associations among changes in work-family conflicts and perceived fairness of housework division across the transition caused by COVID-19. Specifically, increased work-family conflicts predicted the perception of increased unfairness in housework division and vice versa, and changes experienced by husbands were predictive for both spouses. We also found husbands’ (not wives’) more traditional gender attitudes exaggerated the associations between increased work-family conflicts and the perception of more unfairness. We advocate for efforts to facilitate work-family balance and to promote more egalitarian gender attitudes, which is especially crucial because the COVID-19 pandemic and other social changes have reshaped work and family lives and gender role attitudes around the world.