BackgroundShorter telomere length is associated with numerous comorbidities. Several studies have investigated the role of obesity in telomere shortening. In the current systematic review and meta-analysis, we summarized the results of studies that evaluated the association between obesity and telomere length.MethodsA systematic search from Scopus, PubMed, Embase, and ProQuest electronic databases up to 19 March 2021 without language restriction was performed and after data extraction and screening, 19 manuscripts were eligible to be included in the final meta-synthesis.ResultsThe highest category of telomere length was associated with an approximate 0.75 kg/m2 reduction in body mass index (BMI; WMD = −0.75 kg/m2; CI = −1.19, −0.31; p < 0.001; I2 = 99.4%). Moreover, overweight/obese individuals had 0.036 kbp shorter telomere length compared with non-overweight/obese adults (WMD = −0.036; CI = −0.05, −0.02; p = 0.030; I2 = 100%). According to the results of subgroupings, continent, age, and sample size could be possible sources of heterogeneity.ConclusionFrom the results, it was clear that obesity was associated with shorter telomere length. Because of the observational design of included studies, the causality inference of results should be done with caution; thus, further longitudinal studies are warranted for better inference of causal association.