The European olive tree, Olea europaea L., and its polyphenols hold great therapeutic potential to treat neuroinflammation and cognitive impairment. This review examines the evidence for the anti-inflammatory and neuroprotective actions of olive polyphenols and their potential in the treatment of long COVID and neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). Key findings suggest that olive polyphenols exhibit antioxidant, anti-inflammatory, neuroprotective, and antiviral properties, making them promising candidates for therapeutic intervention, especially when formulated in unique combinations. Recommendations for future research directions include elucidating molecular pathways through mechanistic studies, exploring the therapeutic implications of olive polyphenol supplementation, and conducting clinical trials to assess efficacy and safety. Investigating potential synergistic effects with other agents addressing different targets is suggested for further exploration. The evidence reviewed strengthens the translational value of olive polyphenols in conditions involving cognitive dysfunction and emphasizes the novelty of new formulations.