The purpose of this study is to investigate the current state of branded content in popular Korean YouTube channels for children and evaluate its appropriateness. As online content has become an integral part of the daily lives of children growing up in the digital media environment, the digital advertising market targeting children is growing rapidly, with new forms of advertising emerging. Considering children’s immature persuasive knowledge, it is necessary to review various commercial messages that penetrate the online spaces they frequent to create a healthy media environment. This study reviews popular Korean YouTube channels for children from a commercial perspective and discusses the potential impact on children based on relevant theories and previous studies. A total of 298 videos were randomly selected from 13 popular channels, and the influencer marketing status was examined based on the presence of advertising disclosure. Among the 298 videos analyzed, only four contained ad disclosures. In addition, 29 videos were identified as having a clear commercial nature despite the absence of ad disclosure. Furthermore, a significant number of videos without ad disclosures contained commercial messages or inappropriate content for child viewers. This study is the first to review the commercial messages in YouTube content targeted at Korean children, and it has significant academic and practical implications as it provides direction for necessary follow-up research in the future.