The public discourse about teaching has been shaped by actors often far removed from the classroom. In the face of education reform organizations, neoliberal and conservative politicians, and news media that amplify salacious and simplistic stories, teachers' voices have often been drowned out. However, the rise of blogging, social media, and other online platforms provide opportunities for teachers to communicate about their profession with broad audiences. While teachers' online activities--especially in the form of online learning and professional development--have received research interest, that scholarship is often interested in the particular online platforms teachers utilize. In contrast, teachers' shaping and sharing ideas about teaching, the teaching profession, and schooling can be understood as forms of teacher professional public thinking. This research project looks at the motivations, the factors that help maintain, and the meaning of teacher professional public thinking. This research is guided by the following research questions: 1) Why do these teachers take part in professional public thinking? 2) What outside factors have a major impact on their professional public thinking? 3) How do these teachers interpret the influence of their professional public thinking? As an interpretive qualitative study, it analyzes interviews with 12 teacher participants as well as examples of their professional public thinking. That professional public thinking has occurred in the form of blogs, Twitter, TED talks and other media. Many of them have had their work rebroadcast by established media companies, and some of them have had their work go viral. Findings show that (1) teachers are inspired to think publicly about their profession by frustrations over education reform and the desire to share their reflectivity and expertise; (2) professional public thinking is impacted by internal and external factors; and (3) professional public thinking can influence policy locally, buttress the profession's status, and foster dialogue with the wider public. Research implications point to the need for teacher educators and other stakeholders to foster teacher professional public thinking among the next generation of teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]