In Thailand, science, technology, engineering and mathematics (STEM) education is being promoted to support science student teachers by conducting projects to extend their learning skills and to turn them into innovators. This study aimed to develop a professional development programme (PDP) based on biomimicry to improve STEM project creation for science student teachers and to evaluate the implementation result of this programme. The 60-hour programme, designed for 29 science student teachers from a teacher training institute in southern Thailand, was collaboratively developed to align with stakeholders' needs. It comprised four main lessons incorporating biomimicry principles and an eight-step problem-solving approach. The design process included stakeholder input, expert validation, and iterative improvement. The PDP integrated a coaching approach to facilitate problem synthesis and enhance learning outcomes. It underwent multiple stages of design, drafting, and expert validation before finalization. The programme's effectiveness was evaluated through the creativity of resulting STEM projects using class observations, a creativity evaluation form, and interviews. Data analysis employed content analysis and interpretative methods. The implementation resulted in six innovative biomimicry-inspired STEM projects, demonstrating the programme's success in fostering creativity and innovation among future educators. This study contributes to the advancement of STEM education in Thailand by providing a structured approach to developing science student teachers' project creation skills.