Abiotic stresses impact negatively plant growth and productivity worldwide. One promising method to improve plant tolerance to these stresses is through inoculation with endophytic fungi. Endophytic fungi form symbiotic relationships with host plants and can produce bioactive metabolites that induce physiological changes conferring stress resistance. This review summarizes key studies on bioactive compounds produced by symbiotic fungi that enable plants to maintain growth, photosynthesis, and antioxidant activity under stressful conditions. Specific metabolites produced by endophytes such as phytohormones, antioxidants and osmolytes are highlighted for their roles in signalling cascades that counteract damaged caused by stresses. Directions for future research include characterising metabolites of endophyte strains that promote resistance, profiling the mechanisms that make plants more resistant to abiotic stresses, and field experiments to translate controlled results to field conditions. With further elucidation of the metabolic crosstalk between plants and endophytes, microbial inoculation can become an effective and sustainable tool to enhance agricultural drought tolerance.