OBJECTIVE: To examine associations between comfort eating in response to loneliness or stress and weight change during the COVID-19 pandemic among U.S. adults. DESIGN: Quantitative, cross-sectional study. SETTING: The 2021 SummerStyles survey data. SUBJECTS: U.S. adults (≥18 years; N = 4068). MEASURES: The outcome was reported weight changes since the start of the COVID-19 pandemic with four responses: lost weight, weight remained the same, gained weight, and dont know. The exposure variable was frequency of comfort eating in response to loneliness or stress during the past year with three responses: never/ rarely, sometimes, or often/always. ANALYSIS: We used chi-square analysis to examine the independence of survey variables related to weight changes, and comfort eating in response to loneliness or stress during the COVID-19 pandemic. Next, we used a multinomial logistic regression to estimate adjusted odds ratios for weight changes by comfort eating in response to loneliness or stress frequency. RESULTS: Overall, 20.1% of adults reported losing weight, 39.9% remained about the same weight, 30.4% gained weight, and 9.4% did not know about their weight change during the COVID-19 pandemic. Taking comfort by eating in response to loneliness or stress was reported by over 33% of participants (often/always = 8.3%; sometimes = 25.3%). Weight change and comfort eating during the COVID-19 pandemic significantly varied by sociodemographic factors. Respondents that sometimes or often/always reported taking comfort by eating in response to loneliness or stress were more likely to report losing weight (Adjusted Odds Ratio ranges: 1.62-2.99) or gaining weight (Adjusted Odds Ratio ranges: 3.10-4.61) than those who never/rarely took comfort by eating in response to loneliness or stress. CONCLUSIONS: Taking comfort by eating when stressed/lonely was significantly associated with reported weight changes during the COVID-19 pandemic. Weight changes may lead to additional health complications. Implementing evidence-based strategies to reduce loneliness or stress and support healthy eating during the COVID-19 pandemic may benefit weight management and future well-being.