Cyanobacteria play a pivotal role in sustainable agriculture by enhancing soil health and promoting plant growth. These photosynthetic microorganisms contribute to key ecological processes, such as nitrogen fixation and soil stabilization, which are vital for agricultural productivity. This chapter explores the diverse functions of cyanobacteria in agricultural ecosystems, focusing on their ability to produce bioactive metabolites, particularly phytohormones, which influence plant development. The biosynthetic pathways of phytohormones in cyanobacteria and higher plants are discussed, highlighting the potential for manipulating these pathways to augment plant growth. Experimental evidence demonstrating the role of auxins in promoting seed germination and root development is presented, alongside the application of cyanobacterial consortia as biofertilizers for sustainable agriculture. This chapter concludes by discussing future directions for optimizing cyanobacterial applications, emphasizing the need for further research into their genetic manipulation and large-scale implementation in agricultural systems to enhance food security and environmental sustainability.