This study aims to explore the relationships between personality traits and political tolerance. Given that past studies in Taiwan have never investigated the relationships between psychological factors and political tolerance, this study examines how the Big Five personality traits – extraversion, agreeableness, conscientiousness, emotional stability and openness to experience – affect college students’ political tolerance. Using survey data from the panel study on the political socialization of university students in Taiwan, this study employs an ordered logit model to estimate the effects of personality traits on political tolerance. The empirical results show that agreeableness and openness to experience have significant effects on college students’ political tolerance. Specifically, people with higher levels of agreeableness tend to have lower levels of political tolerance; by contrast, those with higher levels of openness to experience are inclined to have higher levels of political tolerance. Besides, conscientiousness and emotional stability also exert some influence on political tolerance. On the other hand, while extraversion seems to have nothing to do with political tolerance, further analysis reveals that extraversion has heterogeneous effects on political tolerance for female and male college students. That is, female college students with higher levels of extraversion tend to have lower levels of political tolerance. Furthermore, conscientiousness also exerts a gender-differentiated effect on political tolerance. Overall, this study confirms that personality traits are important determinants of political tolerance among college students and provides preliminary evidence for heterogeneous effects of personality traits on the political tolerance of women and men. The findings provide new insights into the study of political tolerance and suggest that personality traits should be taken into consideration to explain individual political tolerance apart from contextual, attitudinal and behavioral factors.