Although susceptibility to populist sentiments among adolescents is viewed with concern, research focusing on the nature of populism in youth is still rare. This two-wave study (approx. 10 month) among 9th grade German adolescents (T1: N= 1,205; M[subscript age] = 14.4, SD[subscript age] = 0.6; 52.1% female) examined populist attitudes as a multi-dimensional construct covering the facets of popular sovereignty, anti-elitism, and homogeneity of people. Adopting an inventory originally developed for adult samples, analyses supported the concept's multidimensionality among adolescents. Cross-lagged panel models (CLPM) showed that these dimensions were linked to sociodemographic correlates (i.e., gender, region, school track, and migration background). Additional CLPM analyses examined reciprocal associations with conceptually related political attitudes (i.e., political trust, satisfaction with democracy, intolerance). The results suggested that anti-elitism, in particular, undermines political trust and satisfaction with democracy and give rise to intolerant attitudes. The methodological implications of measuring populism as multifaceted construct among youth are discussed.