Desertification intensified by climate change and unsustainable land use has rendered vast arid and semi-arid ecosystems ecologically degraded and agriculturally barren. Conventional restoration strategies often fail due to neglect of soil microbial processes critical for nutrient cycling, water retention, and plant establishment in degraded soils. This review shows the pivotal role of endophytic microbiomes residing asymptomatically within plant tissues in restoring ecological function in these stressed environments. Endophytes confer drought and salinity tolerance, enhance nutrient acquisition through nitrogen fixation and phosphate solubilization, and regulate host stress hormones and gene expression. Through mechanisms such as osmoprotectants synthesis, biofilm formation, and phytohormone production, endophytes enhance water-use efficiency, promote root development, and increase resilience against oxidative and osmotic stress. Field applications of the endophytic microbiome from the Sahel and Negev deserts to central Asia demonstrate improvements in plant survival, biomass, soil microbial diversity, and carbon input. Advances in nano-formulations, synthetic microbial consortia (SynComs), and CRISPR-Cas9 mediated strain enhancement facilitate cost-effective and scalable inoculation strategies. This review signals a paradigm shift toward microbiome-based restoration, integrating molecular, ecological, and biotechnological insights to establish endophytes as key agents of resilience, soil restoration, and climate-resilient ecosystem recovery.