In cultures with high relational mobility, relationships are free and flexible. People can make new friends easily, and they have the freedom to leave unsatisfying relationships. In cultures with low relational mobility, relationships are more fixed, and people have less freedom to leave relationships. We argue that people experience higher well-being if they have the freedom to exit toxic relationships and find new partners easily. In Study 1, we ran a controlled comparison by testing people all within the same nation. We measured well-being and relational mobility in a representative sample of 22,669 people across China. People reported greater well-being in relationally mobile prefectures. Study 2 found this same relationship across 74,657 people in 34 cultures. Study 3 used a cross-lagged design to give more insight into the direction of the relationship. The results showed that relational mobility predicted later subjective well-being, but not the opposite direction. Overall, these data suggest the cultural environments of relational mobility make people happy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).