This book consists of fourteen chapters dealing with recent research made in the direction of plant hormone and abiotic stress tolerance in crop plants. Chapter One deals with abiotic stress and crop productivity. Chapters Two and Three deal with the role of polyamines, ROS, and melatonin in the regulation of abiotic stresses. Chapter Four extensively elaborates the significance of the multigene family in the improvement of crops under stress conditions. Chapters Five and Six deal with the interaction of plant hormones and their subsequent impact on plant abiotic stress tolerance. Chapter Seven, Eight and Nine comprehensively deal with the role of abscisic acid and gibberellic acid signaling in the regulation of abiotic stress tolerance in crops. Chapters Ten through Thirteen describe the role of brassinosteroids cross talk, interaction and signaling in the regulation of abiotic stress tolerance in crops. Chapter Fourteen deals with the emerging role of oxylipins in the regulation of abiotic stress in crops. Chapter Fifteen deals with the role of jasmonic acid and salicylic acid signaling in the regulation of abiotic stress tolerance. This book has gathered recent information of plant hormone research and abiotic stress tolerance in crops. We hope that this book will be very useful for graduate and post graduate students and researchers.