Algae are photosynthetic micro and macroscopic plants that can fix CO2 and produce biomass faster than their terrestrial counterparts. Algal biomass is enriched with a plethora of biochemicals such as phytohormones, vitamins, minerals, carbohydrates, proteins, and lipids. These molecules act as potent growth- and crop-productivity-increasing molecules and also stimulate soil health by improving microbial community, physicochemical properties, and soil texture. These improvements to crops and soils can aid climate-resilient agricultural practices, playing a critical role in ensuring security in food. Biostimulants, biofertilizers, and soil conditioners from algae can encourage sustainable organic agricultural activities by reducing the application of chemical fertilizers and pesticides in the field. This approach attracts a more resilient agricultural system that is better adapted to cope with the challenges of water and soil pollution by chemicals, pesticides, and herbicide inputs. This chapter’s aim is algae-based solutions for sustainable agriculture to meet food security. It highlights the algae’s role in crop improvements, productivity, yield, soil health in terms of fertility, and microbiome improvements.