Aim <p>Stress is associated with negative health outcomes, with increasing levels observed in adolescents, particularly among females. Despite the known association between low social status and stress, longitudinal studies on stress trajectories and the impact of social status in adolescence remain limited. This study describes mean levels of perceived stress by sex and social status over time, and models group-based trajectories of stress levels and examines the associations between social status at age 15 and these trajectories.</p> Subject and methods <p>Data were drawn from a longitudinal Danish study following participants from adolescence to early adulthood (ages 15–32), supplemented with register data. Stress levels were measured at five time points and analysed by sex across social status groups using various measures of social status. Group-based trajectory modelling was used to identify patterns over time.</p> Results <p>Sex differences in stress levels were observed at ages 15, 18, and 21 but diminished by age 32, as stress levels decreased among females. Low social status at age 15, across all social status measures, was associated with higher stress levels over time. Optimal models identified three trajectories among males (low-stable, mid-stable, and increasing) and four among females (low-stable, mid-stable, increasing, and high mid-peak). Low social status was associated with higher odds of being in all other trajectories than the low-stable trajectory, for both sexes, regardless of the social status measure.</p> Conclusion <p>Preventive interventions should focus on individuals with low social status to reduce high-stress trajectories.</p>