Low health literacy is considered to lead to worse health-related outcomes and behaviors and has therefore been recognized as a social determinant of health. While health literacy and its potential determinants have been studied in adults, little research has been conducted with children. This study aims to address this research gap by investigating factors associated with children’s subjective health literacy. Cross-sectional data was collected from fourth graders at German schools with a self-report questionnaire. Sociodemographic characteristics, health-related attitudes, and motivation were analyzed. We used hierarchical multivariate linear regression to explain variance in the dependent variable “subjective health literacy”. A total of n = 907 fourth graders were surveyed. Regarding health literacy, eight out of ten participants (82.2%) reported that it was “rather easy” or “very easy” to deal with health-related information. Family affluence, but not language spoken at home, was significantly related to subjective health literacy, after controlling for confounding. Moreover, parental health orientation, self-efficacy, and motivation are factors significantly associated with health literacy. Based on the results of this study, it is hypothesized that a general motivation to learn new things about health, as well as an environment promoting health-positive behavior, might foster children’s health literacy.