The Proceedings of the conference "Formal methods in computer-aided design 2025" provide up-to-date insight into an exciting field of research.For the sixth time, the contributions of the conference series "Formal Methods in Computer-Aided Design" (FMCAD) are published as conference proceedings by TU Wien Academic Press. The 2025 edition of the conference series, which has been held once a year since 2006, presents the latest scientific findings in the field of computer-aided design in more than 40 contributions. The contributions cover formal aspects of computer-aided system design including verification, specification, synthesis, and testing.The FMCAD conference will take place in October 2025 in Menlo Park, California, USA. It is regarded as the leading forum in the field of computer-aided design and has offered researchers from both academia and industry the opportunity to exchange ideas and network since its inception. 
