The initial months of COVID-19 forced people to quickly adapt to dramatic changes to their daily lives. As a result of the inevitable decrease in access to social support available during the lockdown phase of COVID-19, countless individuals relied upon their companion dogs and cats. Given the strong connections people often have with their companion animals, this study hypothesized that companion dogs and cats would positively impact guardians’ mental health. Anonymous, cross-sectional online surveys were used to test this premise. A total of 5061 responses, primarily females (89%) from the United States (84%), were analyzed. Results suggest that companion animals played a critical role in helping reduce feelings of depression, anxiety, isolation, and loneliness for a majority of pet guardians. Companion animals also helped increase guardians’ experiences of self-compassion, ability to maintain a regular schedule, feel a sense of purpose and meaning, and cope with uncertainty. This was most pronounced for women under the age of 40 who were highly bonded to their companion animal. In conclusion, our study suggests that a companion dog or cat can buffer the effects of extreme stress and social isolation as witnessed during the COVID-19 pandemic.