Background: Colorectal cancer screening has been associated with a marked reduction in cancer- related mortality, and the achievement of screening targets has been identified as a national objective by the Healthy People 2030 initiative. Although various social determinants of health (SDoH) have been demonstrated to impact healthcare access, the association between food insecurity (FI) and colorectal screening rates (CSR) remains unexplored. As such, we sought to assess the impact of FI on county-level colorectal screening rates (CSR). Methods: Data on county-level colorectal cancer screening and food insecurity rates in 2018 were extracted from the Centers for Disease Control (CDC) PLACES and County Health Rankings & Roadmaps databases, respectively. Notably, FI and CSR were categorized as low (lowest quartile), intermediate (middle two quartiles) and high (highest quartile). Multivariable logistic regression analyses were used to evaluate the association between FI and CSR. Results: Among 3,106 counties, the median CSR was 62.1% (IQR 58.9%–65.2%) and ranged from 39.8% (Kusilvak, Alaska) to 74.4% (Newport, Rhode Island). A majority of counties were urban (Metropolitan: n = 790, 25.4% vs. Urban: n = 1,671, 53.8% vs. Rural: n = 645, 20.8%). Overall, a fourth of counties had high screening rates (Low CSR : n = 788, 25.4% vs. Intermediate CSR : n = 1,545, 49.7% vs. High CSR : n = 773, 24.9%). Similarly, 25.0% of counties demonstrated high FI (Low FI : n = 777, 25.0% vs. Intermediate FI : n = 1,552, 50.0% vs. High FI: n = 777, 25.0%). Notably, counties with increasing FI were markedly less likely to have High CSR (Low FI : n = 353, 45.4% vs. Intermediate FI: n = 370, 23.8% vs. High FI: n = 50, 6.4%)(p<0.001). After adjusting for county-level rurality, population-to-primary care physician ratio, household income, unemployment, race/ethnicity, education and uninsurance, intermediate and high FI was associated with an incrementally lower likelihood of having High CSR compared with low FI counties (ref: Low FI ; Intermediate FI : OR 0.61, 95%CI 0.47–0.80; High FI : OR 0.31, 95%CI 0.20–0.50). Conclusions: Increasing county-level FI was independently associated with markedly lower colorectal cancer screening rates, indicating that FI may play a key role in driving disparities in access to cancer care. As such, policies targeted at vulnerable communities characterized by high food insecurity and social deprivation are critically needed to ensure equitable access to preventive cancer care measures such as colorectal cancer screening.