The COVID-19 pandemic’s global scope and resulting social distancing measures have caused unprecedented economic, lifestyle, and social impacts to personal and relationship well-being. While lockdowns have prompted individuals to increase reliance on intimate partners for support, stressful external contexts can also interfere with partners’ capacity to request and provide support, resulting in relationship dissatisfaction and even dissolution. Guided by a risk and resilience framework, this study examined the impact of perceived stress, social contextual factors, and dyadic coping on self-reported relationship satisfaction changes during the initial United States COVID-19 lockdown period. Participants were adults in romantic relationships who completed an online survey between April 13 and June 8, 2020. Overall, survey respondents ( N = 1106) reported higher perceived stress levels than established population norms, and small but significant decrements in relationship satisfaction. Multivariable models revealed that higher perceived stress levels were associated with lower relationship satisfaction levels. Additionally, dyadic coping was found to moderate the impact of perceived stress on relationship satisfaction (B = .05, 95% CI = .02– .07), suggesting that engaging in dyadic coping buffered individuals from adverse effects of perceived stress on their relationships. Findings emphasize heightened stress experienced by individuals during the pandemic, potential detrimental effects of stress on couple relationships, and suggest dyadic coping may help buffer couples from adverse effects of the pandemic on their relationships. As such, dyadic coping may be an important target for future interventions designed to assist couples during the ongoing pandemic and future pandemics/natural disasters.