Critical thinking (CT) is widely recognized as an important component for effective instruction and learning. Numerous researchers have studied critical thinking and its impact on students and educational institutions at all levels (Pithers & Soden, 2000). Puig et al. (2019) acknowledged that very little research had been done to capture teacher perceptions about the practice and implementation of CT. The purpose of this qualitative study was to investigate teacher readiness to implement critical thinking based on the training and development they received within their teacher education programs. Additionally, this study sought to examine the gaps and barriers that hinder the implementation of critical thinking and the best instructional strategies to support the implementation of CT according to teachers and research. The study was designed using three theoretical frameworks and one instructional design: Constructivist Learning Theory, Experiential Learning Theory, Cognitive Learning Theory and Snyder and Snyder's (2008) Instructional design. Interviews and surveys were utilized to capture pre-service and novice teachers perceptions on critical thinking. Data was analyzed using categorical and content analysis resulting in 4 emerging themes. Themes acknowledged were teachers exposure to skills and practices related to CT, gaps and barriers that hinder CT, the impact of confidence related to CT, and strategies that support the implementation of CT. Barriers that hindered CT were student apathy and teacher confidence, time, foundational skills, and institutional and instructional practices. Strategies and methods outlined as effective by pre-service and novice teachers included questioning, reflection, modeling, real-world experiences, collaboration, and active learning. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]