Adverse childhood experiences (ACEs) are associated with poor mental health. Emerging research demonstrates the protective role of positive childhood experiences, including a positive sense of self and relationships with both humans and animals, in mitigating the impacts of early life adversity on mental health outcomes. This study examined whether benevolent childhood experiences (BCEs) or relationships and interactions with pets during childhood moderated the link between ACEs and current mental health symptoms in a sample of young adults. Students (N = 214) recruited from a public university in the U.S. completed an online survey. The results showed that ACEs were significantly associated with worse mental health symptoms, including anxiety and depression. Neither emotional closeness to a childhood pet dog nor positive interactions with a childhood pet were significant moderators of the relationship between ACEs and mental health. In contrast, more BCEs were associated with better mental health, and their interaction with ACEs was significant such that adversity-exposed young adults with high BCEs reported fewer mental health symptoms than those with low BCEs. The results highlight the need for continued research on differential experiences that may be protective in the relationship between adversity exposures and mental health.