The two-volume set LNAI 16617-16618 constitutes the proceedings of the 30th Pacific-Asia Conference on Knowledge Discovery and Data Mining, PAKDD 2026 Special Session, held in Hong Kong, China, during June 9–12, 2026. The 97 full papers included in this set were carefully reviewed and selected from 728 submissions. These papers were divided into two tracks: the Survey Track, the Main & LLM Track. The Survey Track contains survey papers that are intended to provide a structured synthesis of a particular topic in the area of data mining, including but not limited to theoretical foundations of mining, inference, and learning, big data technologies, as well as security, privacy, and integrity, for the perusal of junior researchers and of experts from other research fields. The Main & LLM Track covers research papers on knowledge discovery, data science, machine learning, and LLMs for data science.