This book constitutes the refereed proceedings of the 17th International Symposium on Search-Based Software Engineering, SSBSE 2025, held in Seoul, South Korea, on November 16, 2025. The 8 full papers, 4 short papers and 2 other papers included in these proceedings were carefully reviewed and selected from 24 submissions. They were organized in the following topical sections: Research Track; RENE/NIER Track; and Challenge Track.