The Cognitive Therapy Theories focus on cognitive structures based on past experiences called schemas in the treatment of clients. It can be argued that the information organized in the form of schemas can facilitate the lives of individuals enabling the systematic use of the information that already exists in the memory, and the new information can be organized around the existing schemas. However, maladaptive schemas developing in the early period of life cause individuals to make erroneous processes and eventually make wrong decisions. For this reason, it is extremely important to know the maladaptive schemas creating negations for individuals and to make preventive efforts for individuals to overcome the negations caused by these maladaptive schemas. In the present study, the effects of the psychoeducation program prepared according to the principles of Schema Therapy on the depression and happiness level of teachers were examined in the framework of the general objectives that were mentioned above. In the present study, the pre-test, post-test, follow-up test, and repeated measurement experimental design (single group repeated measurement) was used. According to the results of this study, it was observed after the Schema Therapy-Based Psychoeducation Program that was applied to the schema therapy group that the program was significantly effective in reducing the depression levels of the experimental group participants, and this effect was permanent in the follow-up tests that were performed afterward. It was also seen that the Schema Therapy-Based Psychoeducation Program was significantly effective in increasing the happiness levels of the experimental group participants, and this effect was permanent in the follow-up tests.