The two-volume set "Advances in Knowledge Discovery and Data Mining" includes the thoroughly peer-reviewed proceedings of the 20th Pacific-Asia Conference on Advances in Knowledge Discovery and Data Mining (PAKDD 2016), which took place in April 2016 in Auckland, New Zealand. The collection contains 91 full papers that were carefully selected from 307 submitted contributions. The papers are organized into thematic sections covering various aspects of knowledge discovery and data analysis. These topics range from classification and machine learning to applications, novel methods and algorithms, opinion and sentiment analysis, clustering, feature extraction, pattern recognition, graph and network-based data, spatiotemporal and image data, anomaly detection, as well as text mining and recommendation systems. The diversity of topics addressed makes this work a valuable resource for professionals and researchers in the field of data science and computer science.