Grad students, with the help of research assistants, are researching the physiological effects of an online HRV biofeedback intervention among public school teachers. Given the need for effective, scalable mental health interventions in education, this pilot study aims to evaluate the feasibility and effectiveness of a six-week online HRV biofeedback-informed breathing intervention for public school teachers. In doing so, it addresses a significant gap in the literature by assessing both psychological and physiological functioning. The results of this study may inform the development of accessible interventions to support teacher resilience and well-being in a work environment that can involve high rates of stress.