The central theme of this work is the development of a number of analogs of Hardy's theorem, which is one interpretation of the mathematical Uncertainty Principle, in settings arising from noncommutative harmonic analysis. A tutorial introduction gives the requisite background material. The techniques used to prove the main results run the gamut of modern harmonic analysis such as representation theory, spherical functions, Hecke-Bochner formulas and special functions. Graduate students and researchers in harmonic analysis will greatly benefit from this unique book.