The ever-growing demand for the implementation of sustainable practices in agriculture, which will be suitable for providing solutions to improve agricultural productivity, has led to the exploration of innovative approaches for achieving sustainable agriculture. This strictly prohibits relying exclusively on fertilizers and pesticides to enhance productivity. The practice of high-input agriculture that relies heavily on agrochemical usage is generally regarded to be harmful to the natural environment and is not considered economically viable. In addition, the changing climate, along with the chemical applications (of fertilizers and pesticides), seriously affect the soil health, pest resistance, and growth patterns of the crops. Therefore, microorganisms of the rhizosphere are being studied to promote crop growth along with control of the growth of the pathogen and resistance against the pathogens. Thus, studies on endophytes are considered as a possible alternative to some of the agrochemicals, thus reducing their harmful impact on the environment. Endophytes are the microorganisms that reside and colonize around the plant tissues including colonization of fungi, bacteria, and mycorrhiza. Endophytes specifically help in promoting plant growth by the utilization of various systematic methods, including biological nitrogen fixation, phosphate solubilization, phytohormone production, tolerance against stress, etc. and also develop resistance against pathogen by the release of specific secondary metabolites. The endophytes can also be regarded as bioinoculants since the establishment of symbiotic relationships can improve crop production. For sustainable agriculture to prosper, a considerable number of fungal and bacterial endophytes are being applied as soil and plant inoculants to boost plant yield without exerting unfavorable consequences on the productivity of the plant. Hence, endophytes can also be used as biofertilizers unlike the chemical fertilizers. The endophytes have proven to be effective in rendering better tolerance against both biotic and abiotic stress. Therefore, the endophytic microorganisms can serve as one of the most important components to maximize agricultural benefits. This chapter deals with the immense role played by the endophytes in improving crop productivity and sustainable agriculture.