“Food agency” is one’s ability to procure and prepare food within the contexts of one’s social, physical, and economic environment. In 2018, we used Amazon TurkPrime to field two large national surveys in the United States (US) to examine food agency and several food- and cooking-related factors. The first survey (n = 1,457) was fielded in a national sample of US adults. The second survey (n = 1,399) comprised of parents of 2–9-year-old children. Analyses included hierarchical linear regression to examine factors that explained variation in food agency and used Poisson and generalized linear models to examine the association between food agency and between cooking behavior and dietary intake, respectively. Cooking skills; food skills; and cooking confidence, attitudes, and perceptions explained a high degree of food agency variance. Higher food agency was associated with more frequent cooking of all meals, more frequent scratch cooking, and less frequent cooking with packaged ingredients among both adults and parents. Higher food agency was also associated with higher consumption of vegetables among both adults and children. Food agency encompasses a number of the interrelated factors important for home cooking and is a useful construct for understanding and promoting home cooking behavior.