Background <p>Positive psychological functions are associated with various health and life outcomes. This study examined the construct of psychological well-being in the multi-ethnic Singaporean population and evaluated the Comprehensive Inventory of Thriving (CIT) scale that captures 18 aspects of psychological well-being.</p> Method <p>A two-wave survey study was carried out with 1349 community-dwelling Singaporean adults, of whom 562 completed the second wave. We compared factor structures that have been reported in other populations. The factor model was further tested for replicability in a subsequent household survey sample (<i>N</i> = 1756).</p> Results <p>A new higher-order factor model emerged in the Singaporean sample consisting of three dimensions: interpersonal well-being, individual well-being, and resistance to threats. The new structure demonstrated gender and age measurement invariance. CIT and the three dimensions had expected associations with mental health symptoms, work/study stress, and participants’ actual social support. The new higher-order factor model was replicated in the subsequent household survey sample. Finally, both CIT and its short form, the Brief Inventory of Thriving (BIT), showed convergent validity, reliability and test-retest reliability in the Singaporean population.</p> Conclusions <p>CIT demonstrated some evidence of construct validity and reliability in the current large samples of Singaporean community-dwelling adults. BIT can be an efficient tool to assess and monitor population general well-being.</p>