The social distancing required during Covid-19 times tended to make people feel lonelier than usual. Those with pets might, however, have experienced this less, because pets are known for fostering their owners’ subjective well-being. Building on a recently published structural equation model, our study enhances the understanding of subjective well-being by including the construct social distancing during Covid-19 times. In order to answer our research question—How does human-pet relationship need support influence subjective well-being by considering social isolation during Covid-19 times?—we build on the basic needs theory, assuming that humans as well as their pets have an inherent need of autonomy, relatedness, and competence. Using a multivariate data analysis method, namely partial least squares structural equation modeling (PLS-SEM), we establish a path model and examine the relationship between human-pet relationship need support and subjective well-being by including psychological distress and social isolation during Covid-19 times as mediators. We operationalize subjective well-being as a three-dimensional construct consisting of positive affect, happiness, and life satisfaction. In a sample of 215 pet owners in the USA, supporting their need increases subjective well-being, and decreases the psychological distress and loneliness caused by social isolation during Covid-19 times. Furthermore, psychological distress decreases subjective well-being, whereas perceived loneliness during Covid-19 times does not. Our main contributions are to not only enhance our knowledge on the importance of human-pet relationships in critical times, but also to provide policy makers with insights into what influences people’s subjective well-being, which is closely related to their psychological health.