A growing body of research has been focusing on the well‐being consequences of migration, yet most of this has overlooked the fact that many migrants experience intragenerational social mobility alongside geographical mobility. Without accounting for the effect of social mobility in working life, the impact of geographical mobility on well‐being cannot be clearly examined. This paper focuses on the most successful migrants, who have started from the bottom and have achieved upward social mobility in the course of their careers, and compares their well‐being with that of native non‐migrants who have experienced a similar intragenerational social mobility trajectory. The analysis is based on a recent national survey in China, which has a representative sample for both the overall population and migrants. Findings show that migrants, whether from an urban or rural origin, have better incomes but significantly lower levels of well‐being than natives, even with a similar career advancement trajectory and the same destination class position. Further exploration shows that the well‐being disadvantage of migrants is mainly due to institutional and sociocultural barriers, rather than to reward differentials in the labour market. This may have a wider implication for migrants across national borders.