The purpose of this study was to analyze student-selected library books for how, if at all, agency is enacted by the characters. This study uses tenets from critical multicultural analysis (CMA) and elements of visual analysis (VA) to guide a critical content analysis of enactments of agency in the most circulated books from three school libraries during the 2019-2020 school year. This study builds on and extends the existing research on agency development in children and demonstrations of agency in children's literature. Data revealed a variety of characters, genre, and contexts within the identified books. Analysis provided evidence that characters in these child-selected books demonstrated enactments of agency in varying ways and degrees across all titles. Following a discussion that is organized around the themes created from the findings, characters are identified as belonging within one of the following agentic groups: activists, survivors, problem solvers, and friends. Implications for practice and research include further study of agency in characters of popular books, how children perceive enactments of agency of the characters, and the need for school librarians and other educators to understand agency development and acknowledging the agency of children as they make choices in the literature they read.