School food refers to any foods that are made available to students on school campuses throughout the school day or in after-school programs. As the prevalence of obesity and diet-related diseases are on the rise among youth, attention is increasingly focused on what students eat at school, where young people spend a large percentage of their time and consume up to half of all their calories. This entry focuses on the three main categories of foods found in schools: (1) federally reimbursable meals, which are sold through the National School Lunch Program (NSLP); (2) what are referred to as “competitive” foods because they are sold in competition with NSLP food; and (3) foods that students bring to school from home or purchase from off-campus vendors.