Philosophy for Children (P4C) hopes to cultivate democratic dialogue as well as critical, creative, and caring thinking; the latter of which has been associated with students' social and emotional competencies (SECs) like empathy and perspective-taking. Yet, empirical, randomized studies on the effectiveness of P4C on students' SECs and sense of autonomy are scant. This paper reports findings from a pilot randomized controlled trial (RCT) assessing preliminary outcomes of the impact of an P4C approach on middle school students' SECs and their feelings of autonomy and classroom supportiveness. Ten classrooms of 6th to 8th grade students (N = 233) were randomly assigned to either receive the intervention or serve as controls. The P4C sessions were facilitated by two experienced P4C educators for one 90-minute session once a week for 8 weeks. Outcome analyses revealed no significant differences between P4C and control students on self-reported classroom supportiveness, empathy, perspective-taking, or altruism, however, P4C students were significantly lower on classroom autonomy and teacher-rated SECs at post-test, compared to controls. Person-centered analyses revealed higher post-test empathy among P4C students who were rated by teachers as having higher SECs as compared to students rated low on SECs at pre-test. Taken together, these findings provide preliminary evidence of the impacts of this type of program for early adolescent students.