This book summarizes the chemical variability and structural diversity of all known hybrid organic-inorganic perovskites subclasses including halides, azides, formates, dicyanamides, cyanides and dicyanometallates. It also presents a comprehensive account of their intriguing physical properties, including photovoltaic and optoelectronic properties, dielectricity, magnetism, ferroelectricity, ferroelasticity and multiferroicity. Moreover, the current challenges and future opportunities in this exciting field have also been discussed. Such a timely book will definitely show the readers a complete landscape of hybrid organic-inorganic pervoskites and associated multifuctionalities.