Students' social goals--reasons for engaging in interpersonal relationships with peers-are consequential for students' interactions with their peers at school and for their well-being. Despite the salience of peer relationships during adolescence, research on social goals is generally lacking compared with academic goals, and it is unknown how these social goals develop over time, especially among high school students. The aim of the study was to assess trajectories of students' social goals and to determine how relevant individual and contextual variables predicted initial levels and trajectories of students' social goals. Participants were 9th through 12th grade students (N = 526) attending a U.S. high school. Students filled out surveys of their social goals (social development, social demonstration-approach, and social demonstration-avoidance) 6 times across 2 school years. Nonlinear growth curve analyses and piecewise growth curve analyses were used to assess trajectories of social goals across time. Students' initial levels of social goals differed based on their gender, grade level, prior achievement, and perceptions of classroom goals structures and peer climate. Furthermore, despite substantial stability over time, the shapes of these goal trajectories were predicted by students' gender, grade level, and perceptions of classroom goal structures and peer climate. In particular, students who perceived an increase in performance-avoidance classroom goals maintained higher demonstration social goals and decreased in developmental social goals over time, and students who perceived an increase in positive peer climate decreased in demonstration-avoidance social goals. Implications and directions for future research on social goals are discussed.