This study investigated nutritional composition and bioactive properties of thinned Shinanogold apples to evaluate their potential as functional food and cosmetic ingredients. Thinned Shinanobold apples exhibited markedly higher vitamin C (16.22 mg/100 g), total phenolics (886.27 mg GAE/100g), and total flavonoids (31.54 mg QE/g) levels than mature apples. The antioxidant capacity, assessed using DPPH and ABTS radical scavenging assays, was significantly higher in thinned apples (74% and 72%, respectively) than in mature apples (48% and 52%, respectively). The tyrosinase inhibitory activity, which is important for melanin reduction, and α-glucosidase inhibitory activity, which play a role in delaying glucose absorption, were higher in thinned apples (67% and 70%, respectively) than in mature apples (X and X, respectively), suggesting potential use of thinned apples as skin-whitening and antidiabetic agents. Furthermore, lipoxygenase inhibitory activity was higher in thinned apples (52%) than in mature apples (42%), suggesting potential use of thinned apples as an anti-inflammatory agent. These findings demonstrate that thinned Shinanobold apples contain bioactive constituents with superior activities compared with mature fruits. In addition, these results highlight the potential use of thinned apples as functional food ingredients and cosmetic agents.