The HEXACO dimensions of personality traits (honesty--humility, emotionality, extraversion, agreeableness, conscientiousness, and openness to experience) have been linked to many adaptive outcomes in physical education-related (PE) settings; yet, little is known about the relationship between personality traits and motivation in students of school PE. Using survey data from 300 (48.8% men, 51.2% women) university kinesiology students, this study explored gender-specific relations between the undergraduate students' HEXACO personality traits and several indices of their motivation recalled from their experiences in school-based PE, namely, enjoyment, self-efficacy, positive affect, perceived autonomy support, and task and ego goal orientation. A second aim was to test differences in these constructs between kinesiology and PE majors. Results revealed that the HEXACO personality dimensions collectively predicted each of the six motivational constructs in females and four in males, extraversion predicted five motivational constructs in females and four in males, and openness to experience predicted three in females and two in males. Compared to kinesiology majors (n = 202), PE majors (n = 98) were statistically significantly higher in extraversion, enjoyment, perceived autonomy support, self-efficacy, and positive affect. Motivationally vulnerable students in PE may be those who are more introverted (shy, passive, and reserved) and open to experience (intellectual, creative, unconventional, innovative, and inquisitive). Further, PE majors might be more likely than kinesiology majors to pursue a vocation as a physical educator in part because they are more extraverted and have had more motivating (i.e., enjoyable, autonomy-supportive, performance-based, and self-efficacious) experiences in school-based PE.