Maternal exercise benefits offspring’s metabolic health with long-term repercussions. Here, we systematically reviewed the effects of maternal exercise on offspring obesity outcomes in adulthood. The primary outcome is body weight. The secondary outcomes are glucose and lipid profiles. Two independent authors performed a search in the databases PubMed, EMBASE, and Web of Science. A total of nine studies with 17 different cohorts consisting of 369 animals (two species) were included. Study quality was assessed using the SYRCLE risk of bias. The PRISMA statement was used to report this systematic review. The results showed that maternal exercise contributes to improved glucose tolerance, reduced insulin concentration, and lower total cholesterol and low density lipoprotein levels in adult offspring in mice, which are independent of maternal body weight and offspring dietary condition. Additionally, in rats, maternal exercise leads to a higher body weight in adult offspring, which might be attributed to the high-fat diet of offspring after weaning. These findings further support the metabolic beneficial role of maternal exercise on offspring in adulthood, although the issue of translating the results to the human population is still yet to be addressed.