The psychological state of athletes exerts a substantial influence on their performance outcomes. Self-esteem, in particular, has been identified as a pivotal factor in determining results at the highest levels of competition in sports. This study explores the relationship between self-esteem and agility performance, as well as its impact on ranking among senior karatekas of the Tunisian National Team. The study sample comprised 36 karatekas (20 males, 16 females; mean age: 22.36 ± 3.83 years; mean weight: 66.5 ± 11.5 kg; mean height: 177.7 ± 7.9 cm), including 13 top-ranked (8 males, 5 females) and 23 lower-ranked athletes (12 males, 11 females). The Rosenberg Self-Esteem Scale was utilized to assess self esteem levels, while the Specific Karate Agility Test (SKAT) was employed to evaluate agility performance. The collection of data occurred during training sessions to ensure consistency. The findings indicated a substantial positive correlation between self-esteem and agility performance (p < 0.001), suggesting that individuals with higher self esteem levels exhibited superior agility. Furthermore, the findings indicated that self-esteem significantly influenced both performance and ranking (p < 0.001), as higher-ranked karatekas consistently exhibited elevated self-esteem and superior agility metrics. These findings underscore the essential role of self-esteem in optimizing physical performance and competitive success, underscoring the necessity for psychological support to enhance self-esteem in elite athletes.