Endophytic microbes, encompassing fungi and bacteria, reside within plant tissues without causing harm, significantly benefiting host plants. These microorganisms enhance nutrient availability through nitrogen fixation, phosphorus, potassium, zinc solubilization, and the production of siderophores and phytohormones. These functions promote plant growth and protect against diverse abiotic and biotic stresses. Additionally, endophytic microbes secrete various hydrolytic enzymes and bioactive compounds, further supporting plant health and sustainability and offering a viable alternative to chemical fertilizers. Recent research has highlighted that endophytes enhance nutrient uptake, stress tolerance, and disease resistance in host plants, leading to improved yields. They exhibit capabilities to remediate heavy metals and organic pollutants and confer tolerance to stress, making them suitable for cultivation in marginal lands. Endophytes mitigate environmental risks associated with conventional agricultural practices by reducing reliance on synthetic fertilizers and pesticides. This chapter synthesizes current knowledge on the role of endophytes in agriculture, emphasizing their sustainable solutions for enhancing crop productivity and overall plant health.