Alzheimer’s disease (AD) significantly impairs the life of an individual both cognitively and behaviorally. Tau and beta-amyloid (Aβ) proteins are major contributors to the etiology of AD. This study used mice modeling AD through the presence of tau pathology to assess the effects of Hericium erinaceus (H. erinaceus), also known as Lion’s mane, on cognitive and non-cognitive behaviors. Despite neurocognitive and neurobiological effects of H. erinaceus being seen in both healthy and transgenic mice, no research to date has explored its effects on mice with solely tau pathology. In this study, mice were placed on a diet supplemented with H. erinaceus or a standard rodent diet for 4.5 months in order to determine the effect of this medicinal mushroom on behavior. Tau mice given H. erinaceus had significantly shorter latencies to enter the center of the open field (OF) (p < 0.05) and spent significantly more time in the open arms of the elevated zero maze (EZM) (p < 0.001) compared to tau control mice. Mice given H. erinaceus spent significantly more time in the open arms of and made more head dips in the elevated zero maze (EZM) (p < 0.05). While H. erinaceus had anxiolytic effects, no improvements were seen in spatial memory or activities of daily living. These findings provide additional support for the anxiolytic effects of H. erinaceus and point to its potential benefit as a therapeutic for anxiety in AD.