Vitamin C is an important nutrient implicated in different physiological functions in humans. Despite its important biological functions, therapeutic applications of vitamin C are rare and its use is further impacted by low chemical stability. Several nano-encapsulation techniques have been described in the literature and yet, there are only a handful of clinical investigations dedicated to unlocking the therapeutic applications of nano-encapsulated vitamin C. Clearly, further investigations are warranted in order to affirm the promising clinical potential of nano-encapsulated vitamin C. In this review, we describe the mechanisms of vitamin C activity as a modulator of crucial therapeutic uses in biological systems. We look at key factors affecting the chemical stability of vitamin C alone and in nano-encapsulated and explore pre-clinical and clinical evidence on current vitamin C nano-formulations along with their therapeutic applications. Finally, we critically appraise the gaps and opportunities prevailing in nano-vitamin C research and its potential translation towards relevant clinical outcomes.