Changes in added sugar intake have been associated with corresponding changes in body weight. Potential mechanisms, particularly the impact of added sugar intake on appetite, warrant exploration. A systematic literature review of randomised controlled trials investigated the association between added sugar consumption and appetite in overweight and obese adults. A systematic search of Medline, Cochrane CENTRAL, Web of Science and CINAHL included studies that examined the relationship between added sugar intake and appetite markers, in comparison with a group with lower added sugar intake. A total of twenty-one articles describing nineteen studies were included in the review. The effect of added sugar on appetite was explored separately by reported comparisons of added sugar type and their effect to three study outcomes: energy consumption (n 20 comparisons); satiety (n 18); and appetite hormones, leptin (n 4) or ghrelin (n 7). Increased added sugar consumption did not impact subsequent energy intake (n 9), nor did it influence satiety (n 12) or ghrelin levels (n 4). Differences in the total daily energy intake were comparable with the differences in energy values of tested products (n 3). Added sugar intake was reported to increase leptin levels (n 3). This review did not find a consistent relationship between added sugar intake and appetite measures, which may be partially explained by variations in study methodologies. There is a need for randomised controlled trials examining a range of added sugar sources and doses on appetite in overweight and obese adults to better understand implications for weight gain.