Previous research established that children with poorer taxonomic knowledge in the food domain display increased levels of food rejection. However, the food domain heavily lends itself to script and thematic conceptual knowledge (e.g., pancakes at breakfast), to which young children already attend. This series of studies investigated the development of conceptual knowledge, specifically in the food domain, and the link with food rejection. Study 1 used a nonconflicting triad task testing children’s knowledge of four subtypes of script and thematic associations (food–food pairs, food–utensil pairs, event scripts, and meal scripts) with children aged 3–6 years living in the United States (18 males and 14 females). Study 2 employed the same design along with a measure of food rejection in 3- to 6-year-olds living in France (67 males and 62 females). There was significant conceptual development in both groups, but thematic food concepts are acquired earlier than meal script concepts. Study 3 investigated the link between thematic and script cross-classification and food rejection in 39 females and 33 males living in France (4- to 7-year-olds). Results demonstrate that children as young as 3 years old are already attending to thematic and script structures to inform food-based decision making. Even more critically, Study 3 showed that increased food rejection tendencies are negatively related to script and thematic understanding in the food domain. Such seminal studies illustrate the importance of conceptual knowledge in children’s interpretation and acceptance of food, highlighting promising avenues for knowledge-based interventions to foster dietary variety.