["Political Psychology, Volume 47, Issue 4, August 2026. ", "\nAbstract\nAlthough previous research has shown that citizens of democratic nations tend to report higher well‐being, the psychological mechanisms underlying this association remain insufficiently understood. Guided by Self‐Determination Theory, the present study examined whether democratic functioning enhances well‐being in part through the satisfaction of autonomy, a basic psychological need. We distinguished between objective democratic functioning, as captured by standardized democracy indices, and individuals' subjective perceptions of living in a democracy. Data were drawn from three large‐scale cross‐national surveys. We tested the explanatory role of autonomy at three levels: between individuals (Study 1, 28 countries), between countries (Study 2, 33 countries), and within‐country change over time (Study 3, 92 countries). Between individuals, between nations and within nations across time, perceived democratic functioning was consistently associated with greater well‐being and lower ill‐being via enhanced autonomy. In addition, we found that these subjective perceptions only partially aligned with countries' objective democracy scores across continents. Findings underscore that the subjective experience of democratic functioning, more than objective democratic conditions, is crucial for supporting autonomy and, in turn, mental health. Implications are discussed in terms of how democratic governance is experienced across nations, alongside study limitations and directions for future research.\n"]