Background <p>Despite extensive research on the association between financial strain and mental distress, little is known about its spousal crossover effect in different-sex couples.</p> Methods <p>Using nationally representative longitudinal dyadic data from the UK and fixed effect models, this study examines the dyadic relationship between financial strain and mental distress among couples, and the different relationship by gendered division of labor in income and housework.</p> Results <p>Our findings reveal that for both the husband and wife, financial strain is not only associated with their own mental distress but also their spouses’ mental distress, although the spousal cross-over effects have smaller effect sizes. Next, the husband’s mental distress associated with his own financial strain decreases as his share of the couple’s income increases, while his income share does not significantly alleviate his wife’s mental distress related to her own or her husband’s financial strain. Lastly, the wife’s share of housework does not modify the effect of financial strain on her husband’s or her own mental distress. These findings suggest the protective role of the traditional breadwinner in alleviating the husband’s mental distress from his own financial strain, but not from his wife’s financial strain, while also highlighting the limited effects of housework in mitigating the psychological toll of financial strain on both partners.</p> Conclusions <p>Overall, these findings provide valuable insights into our understanding of the relationship financial strain and mental distress by incorporating the dyadic perspective and gendered division of labor.</p>