Children with a history of behaviorally inhibited (BI) temperament face a heightened risk for anxiety disorders and often use control strategies that are less planful. Although these relations have been observed concurrently in early childhood, middle childhood, and adolescence, few studies leverage longitudinal data to examine long-term prospective relations between cognitive control and anxiety. Using longitudinal data from 149 adolescents (55% female; from predominantly White middle-class families), we assessed temperament in toddlerhood and cognitive control and anxiety at 4, 12, 15, and 18 years of age. At age 4, separate measures of task switching and inhibitory control were obtained via the Dimensional Change Card Sort and Stroop tasks, respectively. At 12, 15, and 18 years of age, planful control was assessed with the AX-Continuous Performance Test, and anxiety symptoms were assessed via self-report. Growth curve models revealed that children with greater inhibitory control at age 4, regardless of BI status, experienced a sharper increase in anxiety symptoms across adolescence. Children with heightened BI during early childhood displayed lower levels of planful control at age 12, but experienced a more rapid improvement in these skills across adolescence. Children with greater task switching ability at age 4 displayed higher levels of planful control at age 12, but experienced a smaller increase in these skills across adolescence. Finally, children's growth rate for anxiety was unrelated to their growth rate for planful control. These findings reveal that early-life temperament, cognitive control, and anxiety remain interconnected across development, from toddlerhood to at least late adolescence. Public Significance Statement This study indicates that temperament and executive function in early childhood predict the future development of anxiety and executive function across adolescence. However, changes in anxiety across adolescence did not relate to changes in executive function across the same period. Together, results suggest that early interventions may have the best chance of improving adolescents' anxiety trajectories.