The book deals with advanced topics of applied mathematics taught in universities and technical institutions. The subject matter is presented in 15 chapters. The first chapter offers the pre-requisites starting from numbers extending up to complex numbers. Vivid topics on group theory, vector algebra and vector calculus are included. The second chapter offers a comprehensive course on ‘ordinary differential equations (ODE)’ needed in the subsequent discussion. Möbius transformations, Laplace transform, inverse Laplace transform, their applications to solve ODEs, Fourier series, Bessel’s and wave equations are dealt in detail while multi-valued functions, diffusion equation, rotation group and non-relativistic scattering are briefly covered. The book is suitable for one year/two semester course for graduate students with 3 hours weekly credits. The presentation is made as lucid as possible based on the author’s long teaching experience of the subject for over 5 decades at different universities worldwide.