Marine macroalgae, commonly termed seaweeds, play a significant role in the aquatic ecosystem as primary producers. Apart from their immense ecological significance, they have been an age-old source of certain categories of chemical compounds of economic prominence. In recent years, green macroalgae’s contribution has accentuated the industries due to its different facet applications, that is, functional foods, pharmaceuticals, bio-fuels, and energy. To keep in demand with the industry need, seaweed farming both in-shore as well as off-shore is gaining significant attention. The cultivation at a large scale to meet industry demands requires consistent supply and improved yield (per capita), enhancements, or introduction of desired new attributes. To materialize the increasing potential, there is a prerequisite to enhance the genomic insights of these important seaweeds. The sagacity of the genome and its alteration will lead to gaining a complete understanding of the physiology of the species, unlike earlier approaches of genetic mutagenesis. This knowledge of novel molecular techniques will be beneficial to enhance the existing traits and impart novel traits in different varieties of seaweeds for varied applications. This chapter aims at a comprehensive study of recent progress made for green seaweed for various applications. It includes available molecular tools and techniques including transformation methodologies for protoplast/thalli, genome, and transcriptome resources of green seaweeds and the potential of genome editing using the CRISPR/Cas system. The research in seaweed genetics is still in its infancy as compared to that of microalgae and cyanobacteria. This is poised to change in the coming years with the increasing application of seaweeds.