This two-volume set constitutes the proceedings of the 20th International Symposium, ISVC 2025, held in Las Vegas, NV, USA, during November 17–19, 2025.The 54 full papers and 18 poster papers were carefully reviewed and selected from 118 submissions. The papers cover the following topical sections:Part I: Deep Learning; Computer Graphics; Motion and Tracking; Applications; Object Detection and Recognition; Medical Imaging, and Virtual Reality.Part II: Segmentation; 3D; Recognition; Video Analysis and Event Recognition; Biometrics; Visualization, and Poster.