The era of digitized healthcare is transforming rapidly, with intelligent and secure health informatics systems at the heart of this revolution. As artificial intelligence, machine learning, cybersecurity, and digital health technologies continue to advance, their integration into healthcare environments is becoming essential — not only for researchers and innovators but also for start-ups and enterprises aiming to build a smarter, patient-centred future. The need for secure, scalable, and intelligent solutions is driving innovation across hospitals, clinics, public health agencies, and personal health technologies. Recognizing this importance, the International Symposium on Intelligent and Secure Health Informatics Systems (IS-HIS 2025) invites researchers, practitioners, and industry experts to submit original, unpublished work that advances the field of health informatics with a strong focus on intelligence and security. This Symposium aims to explore the latest advancements in artificial intelligence, machine learning, and cybersecurity applied to health informatics systems, enhancing patient care, data security, operational efficiency, and shaping the future of healthcare delivery.