This four-volume set constitutes the proceedings of the 21st IFIP WG 12.5 International Conference on Artificial Intelligence Applications and Innovations, AIAI 2025, which was held in Limassol, Cyprus, during June 2025. The 123 full papers and 7 short papers were presented in this volume were carefully reviewed and selected from 303 submissions. They focus on ethical-moral AI aspects related to its Environmental impact, Privacy, Transparency, Bias, Discrimination and Fairness.