Ultra-processed foods (UPFs) are ubiquitous in the U.S. food supply, while growing evidence shows that UPFs harm children’s health. Schools offer a promising setting to introduce UPF regulation and reduce the availability of UPFs. This brief explores the issue of UPFs in school meals and identifies opportunities and challenges to replace UPFs with more fresh and local foods. Replacing UPFs with less processed ingredients and more fresh foods requires a paradigm shift where schools move away from a heat-and-serve operation toward a model of preparing meals mostly from scratch. This brief discusses challenges schools may experience in reducing UPFs and recommends cross-sector actions to promote the transition toward more scratch cooking in schools.