The purposes of this study were to investigate differences in personality and competitive anxiety depending on types of sports and gender, and to determine the influence of personality on competitive anxiety. Participants included 237 athletes (134 men and 103 women) who participated in the Thailand University Games, 2020. They were classified as individual (n = 114) and team (n = 123) athletes. Personality characteristics and competitive anxiety were assessed by using NEO five-factor inventory and sport competitive anxiety test. Differences between individual and team athletes and between gender were tested by using independent t-test. Relationships between personality and competitive anxiety were analyzed by using Pearson product-moment correlation coefficient. Moreover, multiple regression analysis was used to measure the contributions of personality on competitive anxiety. The results showed that competitive anxiety was significant difference between individual and team athletes (p = 0.03, d = 0.28). However, there was no difference in personality between groups. When compared between gender, there were significant differences in competitive anxiety (p < 0.001, d = 0.52) and the agreeableness (p = 0.04, d = -0.26) component of personality between female and male athletes. From the correlation analyzes, four characteristics of personality showed significant associations with competitive anxiety including neuroticism (r = -0.472, ρ < 0.001), extraversion (r = 0.184, ρ = 0.005), agreeableness (r = 0.147, ρ = 0.024), and conscientiousness (r = 0.202, ρ = 0.002). Among five personality factors, the neuroticism had minimally negative effect on competitive anxiety (β = -0.52) with percentage of prediction of 22%. These can be concluded that types of sport and gender are the important factors affecting personality and competitive anxiety. The athletes with certain personality traits were more susceptible to competitive anxiety. Importantly, the neuroticism could serve as a prediction of the competitive anxiety in all collegiate athletes.