Confidence reflects a belief or faith in oneself, and is measured by embedding ratings within ability tests. The research declaring cross-cultural invariance has examined Confidence using exploratory factor analysis. This is limited to exploring the overall structure or configural invariance, of Confidence. The aim of this study was to examine the measurement invariance of Confidence across two cultural samples, using multi-group confirmatory factor analysis (MGCFA) to extend our knowledge of its structure to metric (item loadings) and scalar (item intercept) properties. In contrast to previous research on school-age children, participants were 1522 adults from Australia (N=833) and Thailand (N=689) who completed the ebilities MAS-2 cognitive ability tests online. Separate confirmatory factor analyses in the cultural samples indicated an acceptable fit of a model with one latent factor representing Confidence. Results of MGCFA supported the configural, metric, and scalar invariance of Confidence across cultures. Evidence for the invariance of a one-factor structure was found across the two national samples. Implications and future research directions in the domain of selection and assessment are discussed.