Trans youth experience discrimination and marginalization in their homes, communities, and schools. Professional school counselors (PSCs) are positioned to support and advocate for trans youth as dictated by professional standards. However, an extensive review of literature revealed a lack of confidence and competence in counselors working with trans youth and their families. Further, there is a dearth of literature that addresses factors leading to increased school counselor competence with trans students. The current study uses a cross-sectional survey design to contribute to the extant literature and explore how PSCs in the United States work with students in the K--12 public school system. Results from multiple regression analyses indicate that PSCs who have had postgraduate training and report personal and professional experiences with trans students are more competent in working with trans students. Implications for PSCs and school counselor education programs are discussed.