Introduction. During a period of global challenges and change, special attention should be paid to retaining young teachers in the teaching profession and finding tools to develop their professional and personal resilience, including through mentoring at school. An analysis of sources revealed the inadequacy of technological solutions for combining the efforts of mentors in developing teacher’s resilience. The objective of the study is to systematize theory and experience to develop a technology for developing teacher’s professional and personal resilience through in-school mentoring to ensure the professional development of teachers in the workplace. Methodology and methods. Relying on the fundamental principles of a systemic, comprehensive, student-centered, axiological, and activity-based approach, an experiment was conducted to develop and implement a technology for developing teacher’s professional and personal resilience through in-school mentoring in schools in the Korocha District of the Belgorod Region in 2022-2025. The methods used were analysis, synthesis, generalization, abstraction, experience study, observation, and interview. Results. A technology for developing teacher’s professional and personal resilience through in-school mentoring was developed. It consists of four stages: diagnostic, design, practical, and corrective. Each stage describes the goal, content, actions of the mentor, actions of the mentee, school capabilities, pedagogical conditions, the nature of the interaction, and the outcome. The main outcome of implementing each stage of the technology was a transition from low to high levels of teacher’s professional and personal resilience. Conclusion: The developed technology possesses scientific novelty, promotes teachers' professional development in the workplace, and is a key factor in developing teacher’s professional and personal resilience through mentoring in schools.