Introduction. In positive psychology, psychological well-being is associated with personal resources that ensure creative processes and positive changes in a person’s life and activities. Considering agency as the main professional and personal resource of a teacher for positive transformations in modern education, we assume that agency acts as such a resource provided that the teacher perceives himself as a psychologically prosperous person. Psychological well-being in the study is considered within the framework of the PERMA model and represents the teacher’s self-representation of the main resources of positive functioning (positive emotions, involvement in relationship activities, meaning and achievement in activities) and his experience of happiness and life satisfaction. The purpose of the study is to study the characteristics of the psychological well-being of a modern teacher and the relationship between the components of well-being and the structure of the teacher’s agency.Materials and Methods. The severity of the components of teachers’ subjectivity was studied using the “Structure of agency” questionnaire (E. N. Volkova, I. A. Seregina). To study psychological wellbeing, the Russian version of the PERMA-Profiler questionnaire was used (O. M. Isaeva, A. Yu. Akimova, E. N. Volkova). 447 people participated in the study, of which 376 people. (84.1 %) – women, 71 people. (15.9 %) – men. The average age of study participants was 37.2 years (standard deviation SD=12.5). Work experience – from 1 year to 47 years.Results. The results of the study showed that the general level of well-being, as well as the values of the main components of well-being among modern teachers, is in the range of average values, however, all components of psychological well-being are expressed among teachers to a lesser extent than among representatives of other professional groups and in general among respondents of the Russian sample. Stratification variables that influence the psychological well-being of school teachers are the characteristics of age, work experience, and qualification category. The psychological wellbeing of teachers corresponds to older age, decreased work experience, and a low qualification category (or lack thereof). Psychologically well-off teachers are characterized by a balanced structure of agency, which presupposes uniform and high expression of all its components. Among the components of agency, psychological well-being is most determined by the teacher’s ability to make personal choice and the development of reflection.Discussion and Conclusions. The teacher’s psychological well-being can be considered as a characteristic of his/her professional socialization connected with the level of students' well-being. The actual level of teacher’s psychological well-being is lower than in the general Russian sample and in the sample of other professional pedagogical groups - preschool teachers. The low level of the teacher's psychological well-being can hinder the teacher's professional development. The teacher's psychological well-being is correlated with the teacher’s agency, in particular, with the teacher's activity, choices and responsibility, reflection. A balanced structure of agency is correlated the psychological well-being of teachers and the understanding another person is expressed to a significant extent.