Saskatoon berry ( Amelanchier alnifolia ) is rich in polyphenols known to modulate oxidative stress and neuroinflammation, key mechanisms involved in Alzheimer’s disease (AD), yet its neuroprotective potential in this context remains unexplored. Here, we investigated two Saskatoon berry extracts, acetonic and ethanolic, using integrated chemical, computational, cellular and in vivo approaches. Antioxidant activity was confirmed in multiple assays, with stronger radical scavenging and moderate reducing capacity. Chemical profiling revealed solvent-dependent differences in phenolic and flavonoid content. In neuroglial models, the ethanolic extract showed mild-cytotoxicity, whereas the acetonic extract exhibited a favorable safety profile. In an amyloid-beta-induced cellular model, the acetonic extract produced only modest effects on viability. Furthermore, fibroblasts assays showed increased total ATP under non-inflammatory conditions, whereas in the LPS-stimulated inflammatory model the extract increased mitochondrial membrane potential. In contrast, in vivo studies using Drosophila melanogaster AD models showed protective effects of the acetonic extract, including reduced ThT-reactive fluorescence and increased retinal thickness, while improved survival was observed in w ¹¹¹⁸ flies. Gene expression analysis of flies’ brain tissue showed altered expression of selected mitochondrial- and immune-related genes. The AD-like model showed increased expression of co1 , nd1 , tfam and dipt , which were significantly reduced following treatment. Overall, these findings identify Saskatoon berry as a novel natural source of bioactive compounds with anti-Alzheimer’s potential and suggest that the in vivo protective effects may involve mitochondrial homeostasis and immune-related processes, warranting future mechanistic studies and neuronal-specific validation in more complex organisms.