Increasingly, social media spaces have become places for teachers to exchange ideas and acquire new information in support of their professional learning. The popular app, TikTok, has become one of the social media spaces that teachers are using for that purpose. Teachers' use of online social media spaces to support their learning may have important implications for professional development and for classroom teaching practices. To gain an understanding of how K-12 teachers are using TikTok, this mixed-methods study was designed to investigate their professional use through an online survey and interviews. A total of 101 participants completed the survey, and 14 survey participants completed follow-up interviews. The teachers in this study were found to use TikTok to attain and share ideas with other teachers and to build and maintain connections with students. With the rise in popularity of social media spaces, including TikTok, these findings have implications for teachers, school leaders, teacher educators, and policymakers. Further, the findings also suggest exploring some larger questions related to social media use by teachers, in general. Policy implications based on the findings are explored.