Unhealthy food and beverage marketing to children, including adolescents, leads to diet-related negative health outcomes. In recent years, food brands have pioneered highly engaging, rewarding, and targeted digital marketing techniques with enormous youth appeal to reach children online. As with traditional TV advertising, digital marketing primarily promotes unhealthy products and negatively affects children’s food preferences and diets. However, online marketing is often disguised within entertainment content, including games and endorsements by celebrities and popular influencers, spreads virally through peer networks, and takes advantage of adolescents’ unique developmental vulnerabilities, including importance of peers and social status, identity formation, and reward sensitivity and risk taking. Online food marketing also disproportionately targets “multicultural” youth, thus the negative effects may be greater for Black and Hispanic youths who face higher health risks and exposure. Moreover, children’s online behavior is tracked and used to target content and marketing messages, threatening their rights to privacy and freedom from exploitation. Yet, parents, educators, and child health providers have very few options to shield young people from digital marketing exposure and resulting harm, and most food marketing policies only address advertising to children younger than 13 years. Government-sponsored restrictions on digital food marketing and online privacy protections for youth are likely necessary.