This book constitutes the refereed proceedings of the 20th International Conference on Persuasive Technology, PERSUASIVE 2025, held in Limassol, Cyprus, during May 5-7, 2025. The 17 full papers and 6 short papers included in this book were carefully reviewed and selected from 49 submissions. They are organized in topical sections as follows: Personalized Persuasion; Theory and Exploration; Design and Solutions; Emotions and Behaviour; Behavior Change Games; Personality and Individual Differences. .