Purpose: To investigate the associations of cardiorespiratory fitness, adiposity, and arterial stiffness with cognition in 16- to 19-year-old adolescents. Methods: Fifty four adolescents (35 girls; 19 boys) participated in the study. Peak oxygen uptake ((V) over dotO(2peak)) and peak power output (W-max) were measured by the maximal ramp test on a cycle ergometer and ventilatory threshold (VT) was determined with ventilation equivalents. Lean mass (LM) and body fat percentage (BF%) were measured using a bioelectrical impedance analysis. Aortic pulse wave velocity (PWVao) and augmentation index (AIx%) were measured by a non-invasive oscillometric device. Working memory, short term memory, visual learning and memory, paired-associate learning, attention, reaction time, and executive function were assessed by CogState tests. Results: (V) over dotO(2peak)/LM (beta = 0.36p = .011) and W-max/LM (beta = 0.30p = .020) were positively associated with working memory. W-max/LM was also positively associated with visual learning (beta = 0.37,p = .009). (V) over dotO(2) at VT/LM was positively associated with working memory (beta = 0.30p = .016), visual learning (beta = 0.31p = .026), and associated learning (beta = -0.27p = .040). (V) over dotO(2)at VT as % of (V) over dotO(2peak), BF%, PWVao, and AIx% were not associated with cognition. Conclusion: Cardiorespiratory fitness was related to better cognitive function, while BF% and arterial stiffness were not associated with cognition in adolescents.