Obesity is increasing in prevalence worldwide and carries a theoretical increased risk of morbidity and mortality in critical illness, including hypercoagulability, thrombosis, and renal dysfunction. Obesity has historically been considered a relative contraindication to candidacy for extracorporeal membrane oxygenation (ECMO); however, recent research has suggested that obesity may be associated with improved outcomes in ECMO. This review was conducted to assess and synthesize the existing literature on ECMO outcomes in the obese population. We searched PubMed, Scopus, and CENTRAL databases for obesity and ECMO outcomes, and articles were screened independently by 2 authors. The selection process yielded 29 articles, with one ambispective and 28 retrospective cohort studies. Analyses of these studies show no evidence of globally increased mortality or complications in obesity. Prospective evaluation is needed to further investigate this relationship, but there is currently no evidence to support using body mass index as exclusionary criteria for ECMO.