This book constitutes the post-conference proceedings of the 12th Multidisciplinary International Social Networks Conference, MISNC 2025, held in Oviedo, Spain, during September 3-5, 2025.

The 42 full papers included in this book were carefully reviewed and selected from 89 submissions. They are organized in topical sections as follows: Multidisciplinary Social Networks Research; Generative AI and the Future of Social Content: Opportunities and Challenges; Advanced Social Computing through AI-centric Multidisciplinary Fusion; Network, Economic and Business Studies.