This study used a convergent, quantitative dominant mixed methods design to investigate the construct of teacher well-being. Three-hundred-forty-five teachers participated in quantitative data collection which included the Teacher Well-being Scale (TWBS; Collie et al., 2016), the Teacher Subjective Well-being Questionnaire (TSWQ; Renshaw et al., 2016), the Workplace PERMA Profiler (Butler & Kern, 2016) and the Brief School Climate Inventory (La Salle et al., 2018). Among these participants, thirteen participated in additional semi-structured interviews. Quantitative data was analyzed using confirmatory factor analysis and item response theory. Qualitative data was analyzed using content analysis. Data were brought together through joint displays and analyzed using a novel process, integrated factor analysis. Quantitative findings suggest that existing teacher well-being scales hold pre-established structural properties and are associated with other, related scales, but item fit varied. Item response theory revealed model-fit challenges using recommended response categories. Model-fit improved for both the TWBS and TSWQ once response categories were reduced. Additionally, some items were flagged for poor fit. Qualitative findings indicated that teacher well-being includes factors at both the individual and environmental level. Specifically, individual dispositions such as having a positive attitude or ability to handle setbacks, supportive leadership, and collaborative school climates emerged as key facilitators of well-being. Job specific stress related to workload and negative relationships emerged as key barriers to well-being. Integration of quantitative and qualitative data was supported by a process of integrated factor analysis. Scale items and qualitative codes were compared for areas of convergence (alignment) and divergence (disagreement). A revised teacher well-being scale is proposed based on integrated findings. Synthesis of quantitative, qualitative, and integrated results suggest the following key findings: (a) teacher well-being is a multidimensional, psycho-social construct that must include both individual and environmental factors; (b) individual dispositions contribute to teachers' experiences and well-being at work; (c) the primary barriers to teacher well-being include job specific stress external to teaching; and (d) revising response categories can lead to stronger use and interpretation of teacher well-being scales. Implications for policy, research, and practice are discussed. [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/en-US/products/dissertations/individuals.shtml.]