Although prior research has considered how friendship quality or quantity influence peer victimization risk and vice versa, considerably less is known about how friendship instability (i.e., high levels of friend turnover) and peer victimization may be related to each other across time. Survey data were collected from 9th grade students (N = 388; Mage = 14.05; 60.60% female; 35.8% male; 1.8% non-binary; 1.9% trans/unsure/something else) across 3-month intervals spanning one school year. Using cross-lagged panel modeling, this study investigated cross-lagged longitudinal associations between friendship instability and peer victimization utilizing three waves of data collected across one academic year. Adolescents experiencing greater peer victimization at the beginning of the school year were more likely to experience friendship instability by the end of the school year. However, friendship instability at the beginning of the school year was unrelated to subsequent peer victimization. Peer victimized adolescents are less likely than their nonvictimized peers to maintain stable friendships over time. Findings suggest that adolescents who are victimized by peers after transitioning to high school may have difficulty maintaining friendships.