This Special Issue on Crustacean Genomics arises from the TCS 2017 conference held in Barcelona, Spain, between 19 and 22 June, 2017. Applications of next generation sequencing have expanded rapidly over recent years, unveiling many new and exciting areas of genomic research. This includes novel insights into physiology, reproductive biology, response to environmental challenges, and their evolutionary history. Despite their importance, crustaceans still lack genomic resources compared with other widely-studied groups such as insects and vertebrates. The present volume integrates a collection of contributions from the speakers, and compiles the main results presented during the symposium. Following the structure of the Crustacean Genomics workshop, contributed papers have been arranged in two main blocks, a first set of studies focused on the use of transcriptomics to investigate crustacean physiology and reproduction while the second set focused on molecular systematics and evolutionary studies.