Selective feeding by overabundant herbivores can considerably alter plant community composition and structure, often benefiting non-native species. White-tailed deer (Odocoileus virginianus) are a dominant herbivore in North America, known for their preference for native plants over unpalatable invasive species. Common buckthorn (Rhamnus cathartica), a widely invasive shrub, is largely avoided by deer, potentially facilitating its competitive advantage against native plants. This study investigates the interactive effects of buckthorn invasion and deer browsing on native woody plants within a post-industrial urban forest undergoing restoration. Specifically, we employed both a long-term observational tree survey and an experimental shrub study to assess buckthorn impacts on native trees and shrubs, and to investigate whether buckthorn presence intensifies deer browsing. For the tree study, we surveyed ten native tree species planted in areas with varying levels of buckthorn invasion to assess tree health as a function of buckthorn and canopy tree cover. For the shrub study, we examined deer and insect herbivory on five deer-resistant native shrubs with and without deer exclusion and buckthorn removal. We found that increased buckthorn cover correlated with reduced health in native tree species, a relationship not found between the trees and native canopy tree cover. We also found that all five planted native shrub species experienced considerable browsing, with deer and insect damage intensifying in the presence of buckthorn. This study highlights the complex interplay between non-native plant invasions and native herbivore activity, demonstrating that buckthorn indirectly facilitates increased deer herbivory on native species. These findings emphasize the need for integrated forest restoration strategies that address both invasive plant removal and herbivore management to support native species recovery.