<p>Loneliness is an emotional experience that can arise even within romantic relationships. Cognitive deficits, such as executive function (EF) difficulties, may contribute to loneliness directly or by creating a gap between partners’ expectations as expressed in inflated relational entitlement. This study examined the relationship between self-reported EF difficulties, inflated relational entitlement, and a question regarding couples’ loneliness using a dyadic approach. A total of 127 couples participated in the study. Results indicated an actor and partner effect of the association between EF difficulties and inflated relational entitlement. Moreover, EF difficulties contributed to loneliness partly through inflated relational entitlement. Among men, EF difficulties were associated with greater loneliness both through their own entitlement and through their partners’ entitlement, and were also linked to their partners’ loneliness via women’s entitlement. Among women, EF difficulties were not directly related to loneliness but showed multiple indirect effects through both their own and their partners’ entitlement. Significant partner effects across several pathways highlight the dyadic nature of these associations. The results may shed a new light on how individual differences in cognitive processes are connected to dyadic processes and relationship dynamics.</p>