Objective: This study was conducted based on the need to enhance early childhood teachers' competency in sustainability education. The goal was to develop a teacher training program that enables educators to have a holistic understanding of sustainability education, foster sustainable habits in their personal lives, and effectively implement sustainability education for young children. Methods: This study developed an educational program to enhance early childhood teachers' competencies in education for sustainable development through analysis, design, development, implementation, and evaluation. The analysis phase involved a review of prior research and literature. In the design phase, the program framework was structured with input from eight experts. The development phase included creating a prototype, which was validated by 15 experts. The program was then implemented with 10 teachers. Finally, in the evaluation phase, data from the implementation were analyzed to assess field applicability and content validity, leading to the final version of the program. Results: The program, aimed at enhancing early childhood teachers' competency in education for sustainable development (ESD), was developed with 8 sessions and 16 classes. It covers three areas: understanding sustainable development, the social, environmental, and economic aspects, and ESD implementation in early childhood education. The program utilizes various teaching methods, including lectures, discussions, workshops, and case sharing. Evaluation includes process and summative assessments, with satisfaction surveys to finalize the program. Conclusions: This program, developed to enhance early childhood teachers' competency in education for sustainable development, focuses on knowledge, skills, and attitudes. It is based on comprehensive analysis, applied in practice, and refined through feedback, increasing its applicability. The program is expected to make a meaningful contribution to ESD for both preschool teachers and children.