Knowledge Discovery (KD) is an interdisciplinary domain focusing upon methodologies for identifying valid, hidden, novel, potentially actionable and meaningful information, from within data of all kinds. Knowledge discovery encompasses an end-to-end process involving: data preparation, the application of learning techniques and the presentation of the acquired knowledge in a manner that is both meaningful and (importantly) explainable. The learning techniques used range from statistically-based data mining, through sophisticated machine learning models to deep learning. Current trends in the field of KD include Explainable AI, Hybrid-learning, and the application of knowledge discovery to ever increasingly diverse data sets.