Mulberry (Morus spp.) is the sole food plant of the domesticated silkworm, Bombyx mori L.. Silk productivity is primarily determined by the nutritional quality of mulberry leaves. Continuous use of fertilizers for decades have sustained leaf yield but has rarely targeted the biochemical composition that silkworm physiology requires. Biofortification is the process of enrichment of protein, micronutrient, and antioxidant concentrations in the harvested leaf, which offers a route to close this gap without additional land or labour. This review synthesizes published evidence across four biofortification strategies for mulberry (i) agronomic mineral management, (ii) microbial and biostimulant inoculation, (iii) nanotechnology enabled nutrient delivery and (iv) genetic variation in leaf composition. For each strategy, mechanisms of nutrient uptake and leaf accumulation are examined alongside documented effects on silkworm nutritional indices, immune competence, and cocoon and silk quality traits. This review also evaluates the comparative advantages and limitations of the four strategies, their practical relevance for smallholder sericulture, and the research priorities, standardized multi-site trials, mechanistic and multi-omic studies, and food-chain safety validation foremost among them, that would move the field from proof-of-concept toward farm-scale recommendation.