Analytical methods of applied mathematics are the subject of this book, which takes the reader from elementary notions of functional analysis to an advanced discussion of systems and control theory. The text begins by reviewing the basics of vector spaces, the theory of which is developed further to include Banach and Hilbert spaces. This provides a strong foundation in functional analysis from which the author can launch a penetrating discussion of duality, distributions, Fourier and Laplace transforms and Hardy spaces. Finally, cutting-edge applications of these techniques to systems and control theory are presented. This text is designed to be useful to working scientists, engineers and students and will appeal to those unfamiliar with the material covered. The author's modern style of exposition provides the motivations of definitions and the ideas underlying proofs without sacrificing mathematical rigour.