This volume constitutes the refereed proceedings of the 21st IFIP WG 11.9 International Conference on Advances in Digital Forensics XXI, which took place in New Delhi, India during January 6-7, 2025.The 10 full papers presented in this volume were carefully reviewed and selected from 25 submissions. These papers were organized into the following topical sections: Image and Video Forensics; Large Language Model Applications; Forensic Investigations; and Digital Forensics Frameworks.