Well-being research and its measurement have grown in the last two decades. The objective of this study was to adapt and validate the Flourishing Scale in a sample of Spanish adults. This was a cross-sectional study using a non-probabilistic sample of 999 Spanish general adult population participants. The psychometric properties of the scale were analysed from an exploratory and confirmatory perspective. Exploratory factor analysis showed a one-factor solution explaining 42.3% of the variance; an internal consistency of .846; temporal reliability correlation of .749; convergent validity with the Satisfaction with Life Scale of .521 and criterion validity with positive and negative affect (PANAS), pessimism and optimism (LOT-R) ranging from .270 to .488. Confirmatory factor analysis testing the one-factor solution showed a χ2 of 65.57 df = 20; CFI of .982, RMSEA of .06, average variance extracted index of .518 and composite reliability index of .841. Results showed that the Spanish version of the FS is a reliable and valid method for measuring high levels of well-being