Incivility involves rude, discourteous, and disrespectful attitudes and behaviours. The present study examined how various temperament traits were related to beliefs of classroom incivility among adolescents. The sample comprised of 222 adolescents (120 boys) between the ages of 12 and 17 (M[superscript age] = 14.07, SD = 1.54) who were recruited from various extracurricular clubs and sports teams in Southern Ontario. Both intentional and unintentional incivility were examined through separate hierarchical multiple regressions. Lower Effortful Control and lower Frustration significantly predicted unintentional incivility. In addition, lower Affiliation and lower Effortful Control significantly predicted intentional incivility. The results are discussed highlighting practical implications in educational settings, as well as suggestions for future research on incivility, given its potential associations with more negative antisocial behaviours. The results suggest that although there may be shared temperament traits of adolescents who take part in classroom incivility, a disposition for specific subtypes may differ based on the specific temperament characteristics of adolescents.