This study determined the relationship between teacher stress sources and teacher self-efficacy among Grade 1 teachers in the Lake Sebu District, Division of South Cotabato. Specifically, it examined the extent of stress sources in terms of personal-related, work-related, family-related, and subject-related domains, and the extent of teacher self-efficacy across classroom management, content knowledge and instruction, organization, relationships, external communication, and self-belief. A quantitative descriptive correlational research design was employed to systematically describe the variables and determine their relationship. Data were collected from 140 respondents selected through Slovin’s formula. Validated survey questionnaires were administered, and the data were analyzed using weighted mean, standard deviation, Pearson product moment correlation, and multiple regression analysis. Findings revealed that both teacher stress sources and teacher self-efficacy were extensive, indicating that stress and self-efficacy were oftentimes evident among teachers. A significant relationship between stress sources and teacher self-efficacy was established, showing that variations in stress levels were associated with changes in teachers’ perceived capabilities. Regression results further indicated that all domains of stress sources significantly influenced teacher self-efficacy, with personal-related stress emerging as the strongest predictor, followed by subject-related and work-related stress, while family-related stress had the least influence. The study concludes that teacher stress is a multidimensional factor that significantly shapes teacher self-efficacy. It is recommended that educational leaders implement targeted stress management programs, strengthen professional development initiatives, and improve workplace support systems. Teachers are also encouraged to adopt effective coping strategies and actively engage in continuous learning to sustain and enhance their professional confidence.