There is increasing interest in leveraging social media to prevent childhood obesity, however, the evidence base for how social media currently influences related behaviors and how interventions could be developed for these platforms is lacking. This commentary calls for research on the extent to which mothers use social media to learn about child feeding practices and the mechanisms through which social media influences their child feeding practices. Such formative research could be applied to the development and dissemination of evidence-based childhood obesity prevention programs that utilize social media. Mothers are identified as a uniquely important target audience for social media-based interventions because of their proximal influence on children's eating behavior and their high engagement with social media platforms. Understanding mothers' current behaviors, interests, and needs as they relate to their social media use and child feeding practices is an integral first step in the development of interventions that aim to engage mothers for obesity prevention. This commentary highlights the importance of mothers for childhood obesity prevention; discusses theoretical and analytic frameworks that can inform research on social media and mothers' child feeding practices; provides evidence that social media is an emerging context for social influences on mothers' attitudes and behaviors in which food is a salient topic; and suggests directions for future research.