Background: Social vulnerability may influence maintaining healthy lifestyle factors among cancer survivors, but few studies have examined associations of both individual- and area-level social vulnerability with these factors. Methods: Using cross-sectional data from the 2011-2023 Maryland Behavioral Risk Factor Surveillance System (BRFSS) survey, we evaluated the association between social vulnerability with obesity (body mass index (BMI) ≥ 30 kg/m 2 ) and physical inactivity (no reported physical activity or exercise in the last 30 days other than their regular job) among cancer survivors ≥ 18 years of age. Individual-level social vulnerability was measured using an adverse social determinants of health (SDOH) burden index, constructed by summing indicators of economic instability (unemployment or living in a household below 250% of the 2023 Maryland federal poverty line), low educational attainment (less than some college), limited healthcare access (no insurance coverage, no access to a healthcare provider, or no medical checkup within the past year), cost-related barriers to healthcare, and non-home ownership. County-level social vulnerability was assessed using the Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI), linked to respondents by county Federal Information Processing Standards (FIPS) codes and averaged across available years (2010-2022). Individuals were classified as residing in counties with high (≥ 0.75) or low (< 0.75) SVI. Survey-weighted multivariable log-binomial regression models were used to estimate prevalence ratios (PRs) with 95% confidence intervals (CIs), adjusting for age, sex, race/ethnicity, time since cancer diagnosis (<5 vs. ≥5 years), and whether an individual is on active cancer treatment. Results: Of the 7,840 cancer survivors, 29.3% were obese, 33.1% were physically inactive, 69.1% reported ≥ 1 adverse individual-level SDOH, and 40.3% resided in high-SVI counties. In adjusted survey-weighted models, increasing individual-level SDOH burden was associated with higher prevalence of physical inactivity. Compared with survivors reporting no adverse SDOH, adjusted PRs for physical inactivity were 1.93 (1.35-2.74) for 1 SDOH, 2.43 (1.70-3.45) for 2 SDOH, and 3.29 (2.28-4.75) for ≥3 SDOH. SDOH burden was not significantly associated with obesity (PR for ≥ 3 SDOH: 1.29 (0.94-1.77)). However, high county-level SVI was associated with obesity (PR: 1.61, 1.81-2.21) but not physical inactivity (PR: 1.34, 1.00-1.81). Conclusions: Individual-level social vulnerability was associated with physical inactivity, whereas county-level social vulnerability was associated with obesity. Findings suggest that intervention strategies to address obesity and physical activity among cancer survivors may require distinct approaches that consider the social context.