This paper provides a comprehensive review of microalgae and cyanobacteria-based biostimulants (MCBs) for agricultural use. Biostimulants are emerging as promising solutions to improve plant growth, nutrient uptake, crop yield, and quality, while reducing environmental impact. MCBS have gained prominence due to their ability to produce high-value metabolites, making them suitable for various agricultural applications. The paper highlights the current state of research and commercialization of MCBS, including strain selection, biomass production, extraction techniques, and application methods. It also discusses the mechanisms of action of MCBS and their potential in addressing current and future agricultural challenges. Despite the promising nature of MCBS, challenges such as production costs, extraction efficiency, and regulatory issues remain. The paper suggests future research directions, including exploring biodiversity, optimizing production processes, and understanding the physiological and molecular mechanisms of MCBS. Additionally, it emphasizes the need for increased awareness among farmers about the benefits of these biostimulants to facilitate their adoption in sustainable agricultural practices.This paper provides a comprehensive review of microalgae and cyanobacteria-based biostimulants (MCBs) for agricultural use. Biostimulants are emerging as promising solutions to improve plant growth, nutrient uptake, crop yield, and quality, while reducing environmental impact. MCBS have gained prominence due to their ability to produce high-value metabolites, making them suitable for various agricultural applications. The paper highlights the current state of research and commercialization of MCBS, including strain selection, biomass production, extraction techniques, and application methods. It also discusses the mechanisms of action of MCBS and their potential in addressing current and future agricultural challenges. Despite the promising nature of MCBS, challenges such as production costs, extraction efficiency, and regulatory issues remain. The paper suggests future research directions, including exploring biodiversity, optimizing production processes, and understanding the physiological and molecular mechanisms of MCBS. Additionally, it emphasizes the need for increased awareness among farmers about the benefits of these biostimulants to facilitate their adoption in sustainable agricultural practices.