Cognitive control allows individuals to regulate their thoughts and behavior in pursuit of their goals and to adapt to changing environmental demands. Neural measures related to cognitive control include the error-related negativity (ERN), error positivity (Pe), and NoGo P3. These Event-Related Potentials (ERPs) develop over time and are associated with social context and psychopathological symptoms. Therefore, the goal of the current cross-sectional study was to clarify the age-effects of cognitive control, its sensitivity to social observation, and its associations with internalizing and externalizing symptoms in a large community sample. A total of 399 adolescents (aged 10-20 years (M = 16.2, SD = 2.60), 42.8% boys/54.7% girls/2.5% other) participated in a (Social) Go/No-Go task as part of the first wave of the Growing Up Together. in Society project. First, our findings showed that ERN amplitudes increased with age, while Pe amplitudes decreased. The NoGo P3 showed an inverted U-shape, with amplitudes increasing first and declining later across age. Second, we found that Pe and NoGo P3 increased under social observation, while the ERN remained stable across conditions. Third, no association between the ERN and neither internalizing nor externalizing symptoms was found, while the Pe and NoGo P3 amplitudes were smaller for adolescents with high externalizing symptoms and the NoGo P3 was reduced for adolescents with high internalizing symptoms. These findings underscore the importance of considering both developmental stage and social context when studying neural mechanisms of cognitive control.