Plant hormones and pheromones are natural compounds involved in the growth, development, and reproductive processes. There is a plethora of studies on hormones and pheromones in terrestrial plants, but such investigations are few in the phycological literature. There are striking similarities between the chemical diversity, biosynthetic processes, roles, and actions of hormones and pheromones in both higher angiospermic plants and algae. However, there are substantial knowledge gaps in understanding the genes responsible for hormone biosynthesis and regulation in algae. Efforts have focused on identifying the genes and proteins involved in these processes, shedding light on lateral gene transfer and evolutionary outcomes. This comprehensive review contributes to benchmarking data and essential biotechnological tools, particularly for the aquaculture industry, where seaweed is economically crucial. Advanced techniques in plant hormones and pheromones can revolutionize commercial aquaculture by using synthetic analogs to enhance growth, yield, and reproductive control, thereby addressing seasonal limitations and enabling sustainable seedling production. To the best of our knowledge, this is the first comprehensive review that focuses on biosynthetic pathways and modes of action (of five plant hormones and five pheromones), roles (of 11 hormones and 29 pheromones), and extraction protocols (of four hormones and six pheromones) reported in the phycological domain.