Previous research on the impact of gender stereotypes on female adolescents' feeling of belonging to peer groups has focused on STEM classrooms and activities. This study expands this research and examines if perceptions of group-held gender stereotypes are related to adolescent girls' feelings of belonging to other social groups. Girls (N = 110) in advanced science and math classes (primarily 9th grade) completed an online survey that included questions about three groups: their science class, their close friendship group, and another peer group of their choosing, classified as their most important group (MIG). Questions about the groups included belonging, their perceptions of the group's gender stereotypical beliefs, and additional social contextual variables that are associated with belonging for girls--presence of close friends, presence of a best friend, and the number of girls relative to boys. Results indicated that girls perceived the different groups to hold different levels of gender stereotypical beliefs. Perceptions that a group held more traditional stereotypical beliefs was negatively correlated with belonging to each of the three groups. Regression analyses indicated the number of friends and perceptions of more traditional stereotypes predicted belonging to MIGs and science classes. Findings suggest that gender stereotypes may be an important factor in how adolescent girls perceive their belonging in many adolescent groups.