"Morrey Spaces" is a specialized book that focuses on the latest research regarding the theory of Morrey spaces in connection with harmonic analysis. The author, David Adams, addresses three central aspects of these spaces in these lecture notes. These include the determination of the integrability classes of the trace of Riesz potentials of any Morrey function, the analysis of the dimensions of singular sets of weak solutions to partial differential equations (such as the Meyers-Elcart system), and the investigation of 'complete' interpolation results for linear operators between Morrey spaces. This book is a valuable reference for students and researchers interested in potential theory, harmonic analysis, partial differential equations, and the theory of Morrey spaces.