Teacher content knowledge influences effective teaching practice. It enables effective understanding, application and teaching of concepts, alongside confidence and competence to apply this to broader world contexts. In Australian secondary schools, food literacy education is mainly taught through home economics subjects, making teacher content knowledge of this concept important. This study investigated and compared the understanding of food literacy of in-field and out-of-field Queensland home economics teachers. A survey was conducted of 117 Queensland Year 7–10 home economics teachers who teach Design and Technologies. Of these, 78% (n = 72) were in-field and 21% (n = 19) were out-of-field teachers (26 participants did not provide demographic data). Inductive qualitative data analysis was performed followed by triangulation with contemporary literature, to identify similarities and differences in their understanding of food literacy. Respondents aligned food literacy with food knowledge, skills and critical thinking; however, few identified connections between food literacy and families. All definitions lacked reference to the influence of attitudes, emotions, culture, society, politics and economics on food consumption. In-field teachers indicated a greater depth and complexity in their understanding in comparison to out-offield teachers. This has implications for teaching effectiveness, student learning and professional learning needs of the broad spectrum of home economics teachers in the current workforce.