Loneliness, a significant public health issue, was exacerbated during the COVID-19 pandemic, particularly in disaster-prone regions like the U.S. Gulf Coast. This study examined how social and built environmental factors were associated with pandemic-related disruptions and loneliness among respondents from the third wave of the Survey of Trauma, Resilience, and Opportunity among Neighborhoods in the Gulf (STRONG). Using a retrospective measure of loneliness (pre-pandemic vs. during pandemic), we found that loneliness increased significantly during the pandemic. Using a measure of routine behavior disruptions and measures of both objective (e.g., parks, walkability, etc.) and subjective (e.g., neighborhood safety, social cohesion, etc.) environmental factors, we found that disruptions to daily routines strongly predicted higher loneliness, and subjective measures, such as neighborhood safety, social cohesion, and lacking post-disaster social support, were more salient predictors of loneliness than objective factors such as the number of parks in one's neighborhood. Difficulty accessing green spaces and housing distress were linked to greater COVID-19 disruptions, indirectly contributing to loneliness. These findings highlight the importance of safe, supportive, and accessible social and physical environments in mitigating loneliness and enhancing community resilience during crises.