Unhealthy-weight status may represent a precursor of poor actual (AMC) (i.e., process- and product-oriented) and perceived (PMC) motor competence. AMC and PMC represent key elements favoring long-term commitment in sports and day-to-day life physical activity. In fact, the development of AMC and PMC during the primary school years could help to counteract weight-related negative effects (i.e., overweight or obesity) that are responsible for sedentary or unhealthy behavior across the life span. Therefore, this review aimed to provide a synopsis of the current research investigating the relation of AMC and PMC with weight status and in the context of potential gender differences. Systematic research in five electronic databases (PubMed, Web of Science, EMBASE, CINAHL, Scopus) was conducted from April 2021 to May 2021 in compliance with PRISMA guidelines. Studies were included if they involved obese or overweight youth (6–10 years) with no physical or cognitive impairment and used a longitudinal or a cross-sectional assessment of motor competence and perceived motor competence outcomes. After the selection process and after duplicates were removed, the final sample included 27 studies. Most of the studies reported that AMC and PMC are negatively associated with weight status, with male and females differing from each other in overall and subtest (locomotor, object control, and stability skills) AMC scores. However, according to a risk of bias assessment, the level of evidence linked to the association of AMC (process and product) and PMC with weight status (BMI) remained uncertain and lacking, respectively. Further high-quality studies are warranted to improve the understanding of AMC and PMC in relation to weight status, which appears to be differently expressed by gender in primary school years. Regardless, based on the current quantitative data, the emerging inverse association between AMC/PMC and weight status implies that it would be best to limit sedentary behavior by including daily lessons in physical education to limit unfavorable conditions (i.e., obesity and overweight) during the school years.