The research literature reports that teacher collaboration has great potential to increase various teachers’ competencies; however, less has been said about how leaders can facilitate and support the development of these collaborations. This study examines the relative impact of distributed leadership practices, teacher professional learning, and innovative climate on teacher collaboration. Data are from the Organisation for Economic Cooperation and Development (OECD) 2018 Teaching and Learning International Survey (TALIS). The sample consists of 2,324 teachers from 159 US lower secondary schools. Results indicate that distributed leadership has a direct and indirect impact on teacher collaboration in that professional learning and innovative climate serve as mediators for the leadership–collaboration relationship. The findings imply a potential benefit to be gained from distributing leadership among various stakeholders throughout the school, as well as expanding access to improve collaborative pedagogical practice among teachers.