COVID-19 has given rise to a myriad of social, psychological, and health-related complications. The specific mental health implications of COVID-19 are still being uncovered, but we know that there are likely to be negative outcomes for many people. This is particularly the case for vulnerable members of the community, such as those with high health anxiety, and under conditions where individuals feel isolated or disconnected from others. The objective of this study was to examine whether the level of socially motivated Internet use acts as a buffer of the relationship between health anxiety, isolation behaviors, and depression. Participants (N = 473; 67.3 percent female; Mage = 23.03, SD = 7.50) from Australia completed self-report measures during the height of the national pandemic restrictions (April-May 2020). A regression analysis revealed positive relationships between health anxiety and isolation behaviors on depression and highlighted a three-way interaction effect. Specifically, health anxiety was significantly negatively associated with depression when participants engaged in fewer isolation behaviors. However, at higher levels of isolation behaviors, the relationship between health anxiety and depression was attenuated for participants with greater levels of online social connection. The findings suggest that online social connection buffered the negative effects of health anxiety under conditions of isolation. These results offer promising avenues to mitigate against vulnerabilities during the pandemic and highlight the need to promote alternate social support mechanisms in the absence of face-to-face connection.