Psilocybin, the naturally occurring psychedelic compound produced by hallucinogenic mushrooms, has received attention due to considerable clinical evidence for its therapeutic potential to treat various psychiatric and neurodegenerative indications. However, the underlying molecular mechanisms remain enigmatic, and few studies have explored its systemic impacts. We provide the first experimental evidence that psilocin (the active metabolite of psilocybin) treatment extends cellular lifespan and psilocybin treatment promotes increased longevity in aged mice, suggesting that psilocybin may be a potent geroprotective agent.