This book originates from the International Workshop on Operator Theory and its Applications (IWOTA) held in Canterbury, University of Kent, UK, in August 2024. It includes both original research articles and broad survey articles on current developments in the field. IWOTA is a major series of annual workshops in mathematical analysis which covers operator-theoretic aspects of topics such as complex analysis, harmonic analysis, linear algebra, random matrix theory, mathematical physics, and their applications, such as control theory, signal processing and AI.