Intergroup contact has long been established as a prejudice-reduction tool in divided societies, with contact being particularly effective during adolescence. A large proportion of evidence, however, draws on cross-sectional surveys or analytical approaches that do not distinguish between- and within-person effects. In the present research, we address this by exploring the potential of intergroup contact longitudinally on social cohesion-related outcomes amongst youth (aged 14-19) in Belfast (Study 1, N = 231) and Bradford (Study 2, N = 159). Measures included intergroup contact, outgroup attitudes, intergroup anxiety, outgroup empathy and outgroup prosocial behaviour across three time points. Using random-intercept cross-lagged panel models, results demonstrate between-person associations of contact with our outcomes, but limited within-person changes. Our findings demonstrate the potential and limitations of intergroup contact for social cohesion-related outcomes for youth growing up in divided societies, pointing to the need for developmental-focused future research.