This book begins with an essential background discussion of the many applications and drawbacks for paraxial beams, which is required in the treatment of the complex space theory of spatially localized electromagnetic waves. The author highlights that there is a need obtain exact full-wave solutions that reduce to the paraxial beams in the appropriate limit. Complex Space Source Theory of Spatially Localized Electromagnetic Waves treats the exact full-wave generalizations of all the basic types of paraxial beam solutions. These are developed by the use of Fourier and Bessel transform techniques and the complex space source theory of spatially localized electromagnetic waves is integrated as a branch of Fourier optics. Two major steps in the theory are described as: 1) the systematic derivation of the appropriate virtual source in the complex space that produces the required full wave from the paraxial beam solution and 2) the determination of the actual secondary source in the physical space that is equivalent to the virtual source in the complex space.