Appearance-related self-esteem is a facet of body image that encompasses the evaluative components of an individual's self-concept that pertains to their own physical appearance. Knowledge regarding how appearance-related self-esteem functions in adolescent social groups is scant in the literature and there is limited research using linear methods suggesting that adolescents can influence the appearance-related self-esteem of their peers. Given the negative consequences of negative feelings about one's appearance later in life, I examined how appearance-related self-esteem develops and relates to adolescent social processes during the transition to middle school. This dissertation investigated how appearance-related self-esteem related to the social processes of selection, similarity, and influence. I further explored the effect of gender on social processes and appearance-related self-esteem. Appearance-related self-esteem was not related to social processes of selection, similarity, or influence. Gender similarity was present in the network, such that adolescents were more likely to select same-gender peers than other-gender peers. Additionally, an effect of gender on appearance-related self-esteem was present, such that boys' appearance-related self-esteem increased over time more than girls'. Findings from the current dissertation provide foundational first steps in identifying the ways that peers impact appearance-related self-esteem during adolescence and provide insights toward understanding how different gender pathways around appearance-related self-esteem may develop over time.