Objective: The purpose of this study was to determine the relationships among sex, race/ethnicity, and food security with the likelihood of cancer, diabetes, cardiovascular disease, and lung disease for older adults. Method: Complex sample analysis by logistic regression models for chronic diseases were conducted from National Health and Nutrition Examination Surveys, 2011 to 2012 and 2013 to 2014, for N = 3,871 adults aged ≥55 years. Results: Being female with low food security was associated with lung disease and diabetes. Poverty, rather than low food security, was associated with cardiovascular diseases. Minority status was independently associated with low food security and diabetes. Discussion: Food insecurity, sex, and race/ethnicity were associated with chronic diseases in a representative sample of U.S. older adults.