The teaching profession has long been recognized as highly demanding of its practitioners (Johnson et al., 2005; Travers, 2001), with most teachers navigating multiple career challenges including heavy workloads, difficulties supporting students' varying needs, struggles with classroom management, isolation from colleagues, limited job resources, low wages, and low professional prestige (Curbow et al., 2003; Day & Qing, 2009; Montgomery & Rupp, 2005, Raskin et al., 2015; Veenman, 1984). These negative job-related experiences have serious implications for the field: attrition rates in the profession are high, with recent reports estimating that 30% to 50% of teachers leave the profession, and about two-thirds of this overall attrition due to reasons other than retirement (Carver-Thomas & Darling-Hammond, 2017). Given the steep importance of teachers for students' positive lifelong development (Aaronson et al., 2007; Chetty et al., 2014a, 2014b; Nye et al., 2004; Rivkin et al., 2005) fully understanding the lives of teachers and using this information to best support them should be a high priority to educational researchers, policymakers, and stakeholders.

We focus here on teachers' well-being, a topic that has gained increasing attention over the past 15 years. Merriam Webster's Dictionary defines well-being generally as “the state of being happy, healthy, or prosperous” (Well-being, 2019). In the field of education, investigations of teachers' well-being have focused primarily on stress, burnout, and mental health symptomatology (clinical depression and anxiety) as indicators of teachers' well-being. Stress, specifically work-related stress, is the most immediate outcome of teachers' challenging professional circumstances, and is defined by Merriam Webster's Dictionary as “a state of mental or emotional strain or tension resulting from adverse or very demanding circumstances” (Stress, 2019). Burnout, a more distal indicator of overall well-being, is considered the endpoint of an individual's unsuccessful coping with long-term stress (Jennett et al., 2003). Among teacher populations, burnout has traditionally been considered a combination of emotional exhaustion, depersonalization (a teacher's cynical attitudes toward students or colleagues), and reduced personal accomplishment (Maslach & Jackson, 1981; Maslach et al., 1996). Clinical depression and anxiety are additional, more distal, indicators of overall well-being and are closely related to individuals' long-term experiences with stress and burnout in the workplace (Rada & Johnson-Leong, 2004; Whitebird et al., 2013). Depression is considered a dampening of positive affect with symptoms including fatigue and feelings of worthlessness whereas anxiety is characterized by excessive worry or fear (American Psychiatric Association, 2013). In the next section, we provide a review of relevant research regarding the current state of knowledge of teachers' well-being as indicated by their stress, burnout, and mental health symptomatology including the sources of influence on these factors, the implications these factors hold for both teachers and students, and notable directions for future research, policy, and practice.