Background <p>Schoolteachers’ personal health and wellbeing are priority to ensure quality teaching, positive student outcomes and improving teacher retention. With limited-availability of validated tools to measure teacher food and nutrition (FN) as a component of wellbeing, this study aims to evaluate the content validity of the Teacher Food and Nutrition-related health and wellbeing Questionnaire (TFNQ) to fill this gap.</p> Method <p>A two-round Delphi was used to refine the questionnaire and establish content validity. Round-one reviewed constructs and lifestyle covariates (LC) for inclusion. Round-two considered construct phrasing, appropriateness of scales and questionnaire order. Descriptive and thematic analyses were conducted.</p> Results <p>Round-one included 23 international experts, with 19 also participating in round-two. After round-one, seven constructs and three LC were removed with two constructs revised into four concise new groupings to refine the TFNQ. In round-two 83% of experts agreed with questionnaire order, and feedback indicated only minor adjustments. The final TFNQ contains 26 FN and wellbeing constructs and three LC.</p> Conclusion <p>This Delphi study established content validity of the TFNQ to appropriately measure key aspects of FN as a component of wellbeing in schoolteachers. Future testing will evaluate the TFNQ construct validity and reliability.</p>