Recommendations for increasing children’s daily physical activity (PA) call on classroom teachers to assume an activist role at school. This study examined relationships among preservice classroom teachers’ (PCT; n = 247) biographical characteristics, perceptions and attitudes regarding school PA promotion (SPAP). Results indicated participants who completed SPAP-related college coursework and had PA-related teaching/coaching experiences reported higher SPAP competence. Significant relationships were found among BMI, personal PA competence and SPAP competence in the contexts of PE and extracurricular settings. Personal PA competence and SPAP competence at recess and in the classroom predicted 19% of the variance in SPAP attitudes. Experiences in PA settings and preservice training may have important implications for the overall success of efforts to enhance school PA promotion.