Theoretically, populism has been conceptualized as a political ideology with three sub-dimensions: anti-elitism attitudes, a preference for popular sovereignty, and a belief in the homogeneity and virtuousness of the people. However, empirical research to date has treated populist attitudes as a unidimensional construct. To address this issue, we propose to conceptualize populist attitudes as a latent higher-order construct with three distinct first-order dimensions. A 12-item inventory was developed using two survey studies conducted in Switzerland in 2014 and 2015. Exploratory and confirmatory factor analyses were used to test the construct validity of this measure of populist attitudes. The measurement that is proposed allows for a fine-grained study of populist attitudes in the general public.