The LNCS 15915 constitutes the proceedings from the 38th International Conference on Computer Animation and Social Agents, CASA 2025, held in Strasbourg, France, during June 2–4, 2025. The 20 papers (17 from the main conference and 3 from the AniNex workshop) presented were carefully reviewed and selected from 82 submissions. These papers focus on various aspects of Computer Animation and Social Agents, such as Motion Capture & Retargeting, Physics-based Animation, Vision-based Techniques, Behavioral Animation, Facial Animation, Image-based Animation, Virtual Humans, Crowd Simulation, AI-based Animation, Deep Learning Methods, Virtual Humans and Avatars, and 3D Physiological Humans