Approximately one in four Australian children aged 5-17 years are overweight or obese. Most of the health effects of overweight and obesity in childhood do not eventuate until into adulthood; therefore, motivation for children to have a healthy diet may be low. This scoping review examined the literature for associations between diet quality in 5-18 year olds and "school-valued" outcomes including student attendance, academic performance, behaviour at school and mental health. A literature search for studies that assessed dietary intake and at least one "school-valued" outcome in schoolchildren, in highly developed countries was conducted. After applying selection criteria, 35 studies were included examining academic performance (46%), behaviour (11%), mental health (31%) and 11% examining two of these outcomes each. No relevant studies addressed attendance. In general, dietary factors including consumption of fruit and vegetables, discretionary foods and/or beverages, or overall diet quality, were suggested to be correlates of the "school-valued" outcomes. However, the evidence is not comprehensive. This review elucidates the extent and nature of available literature, and provides a basis for future research where the potential benefits of diet on "school-valued" outcomes can be thoroughly explored.