Breakfast has been claimed to improve cognitive function and academic performance, leading to the provision of breakfast initiatives by public health bodies. Children may be particularly sensitive to the nutritional effects of breakfast due to greater energetic needs compared to adults. However, there is a lack of acute intervention studies assessing what type of breakfast is optimal for cognitive performance. In this paper, the impact of breakfast-based glycemic response on cognition in children will be reviewed. The data suggest that a more stable blood glucose profile which avoids greater peaks and troughs in circulating glucose levels is associated with better cognitive function across the morning. Although the evidence to date is promising, it is currently insufficient to allow firm and evidence-based recommendations. What limits our ability to draw conclusions from previous findings is that the studies have differed widely with respect to subject characteristics, cognitive tests used, and timing of cognitive assessment. In addition, few studies have profiled glycemic response in children specifically. There is, therefore, an urgent need for hypothesis-driven, randomized, controlled trials that evaluate the role of different glycemic manipulations on cognition.