Background <p>Understanding differences in non-game performance indicators—spanning physical, motor, technical, tactical, and psychological domains—may assist athlete profiling and monitoring in youth basketball. However, comparatively little is known about whether standardised psychological measures differentiate competitive standards in youth basketball.</p> Objectives <p>This study aimed to quantify mean differences in non-game performance indicators between elite and sub-elite South Australian youth basketball players using a quantitative cross-sectional design.</p> Methods <p>All South Australian under-16 and under-18 Division 1 and 2 district basketball players were invited to participate. A total of 174 players (n = 98 [56%] male), including 125 elite and 49 sub-elite players, were assessed. Non-game performance indicators included anthropometric, physical fitness, movement skill, and psychological measures. Generalised linear models adjusted for age, sex, and biological maturation were used to quantify differences between elite and sub-elite players. Differences in means were expressed as partial eta-squared (η²) effect sizes.</p> Results <p>After adjustment, elite players demonstrated significantly higher confidence (η² = 0.138), instrumental leadership (η² = 0.123), competitiveness (η² = 0.120), and body mass (η² = 0.074) compared to sub-elite players.</p> Conclusions <p>Significant psychological and anthropometric differences exist between elite and sub-elite youth basketball players. These findings support the inclusion of psychological assessment within multidimensional athlete profiling and monitoring frameworks, although longitudinal studies are required to establish their predictive value for future playing success.</p>