<p>The current measures of Propensity to Trust in the literature have suffered from reliability and validity issues as well as a lack of evidence of invariance across cultures. To address these concerns, we conducted three studies to develop a propensity to trust measure that possesses strong psychometric qualities and cross-cultural invariance. In study 1, we created potential new items and estimated content validity of each item in a sample of students. In study 2, we collected data from 2786 working adults in 30 countries and used these data to test the factor loadings, reliability, and invariance of the new scale across 6 GLOBE clusters. This process created a 5-item propensity to trust measure that has a Cronbach alpha greater than 0.70 for each GLOBE cluster. Tests of invariance indicate configural invariance and strong support for metric invariance. We reclassified the data by the cultural variable of “tightness” or “looseness” as defined by Gelfand et al. (2011) for 9 of the countries in this study and found our scale had configural invariance as well as metric and scalar invariance. In study 3, we examined the convergent and discriminant validity and found evidence supporting the construct validity of the new scale. This is the first measure of propensity to trust that has been demonstrated to be culturally invariant. With a rapidly growing body of research being conducted across international cultures, this would be an important development for the field.</p>