This book constitutes the thoroughly refereed post-workshop proceedings of the workshops that were held in conjunction with the 23rd Pacific-Asia Conference on Knowledge Discovery and Data Mining, PAKDD 2019, in Macau, China, in April 2019. The 31 revised papers presented were carefully reviewed and selected from a total of 52 submissions. They stem from the following workshops: · PAISI 2019: 14th Pacific Asia Workshop on Intelligence and Security Informatics · WeL 2019: PAKDD 2019 Workshop on Weakly Supervised Learning: Progress and Future · LDRC 2019: PAKDD 2019 Workshop on Learning Data Representation for Clustering · BDM 2019: 8th Workshop on Biologically- inspired Techniques for Knowledge Discovery