<p>Mycorrhizal symbiosis is a key biological strategy for improving nutrient acquisition, stress tolerance, and soil health in crop production systems. Mycorrhizal fungi colonize plant roots and form specialized interfaces through which phosphorus, nitrogen, micronutrients, and water are transferred from the soil to the host plant in exchange for photosynthetically derived carbon. These interactions can enhance plant growth, yield, and quality while reducing reliance on synthetic fertilizers and other agrochemicals. Although most previous work has focused on arbuscular mycorrhizal fungi (AMF) in field crops, many economically important species host a wider range of mycorrhizal types and experience intense abiotic and biotic stresses. This review synthesizes current knowledge on the structural and functional diversity of major mycorrhizal associations, arbuscular, ectomycorrhizal, arbutoid, ericoid, and orchid mycorrhizae, in relation to crop performance. We first describe how these symbioses enhance nutrient uptake and utilization, including extension of the soil exploration zone by fungal hyphae, mobilization of poorly available nutrient pools, and regulation of nutrient transporter expression. We then examine the roles of mycorrhiza in mitigating drought, salinity, heavy metal toxicity, temperature extremes, and pathogen pressure, with emphasis on physiological and emerging molecular mechanisms such as hormonal signaling and activation of antioxidant and defence pathways. Selected case studies highlight improvements in yield, product quality, and functional metabolites across fruits, vegetables, ornamentals, and medicinal plants. By integrating evidence across different mycorrhizal types and crop species, this review underscores mycorrhiza as a multifunctional biotechnological tool rather than only a biological fertilizer. It also identifies key research gaps and practical considerations for deploying diverse mycorrhizal inoculants to support climate-resilient and sustainable production systems.</p>