The global obesity epidemic is well established, with increases in obesity prevalence for most countries since the 1980s. An updated American Heart Association scientific statement on the role of obesity in cardiovascular disease was published in Circulation on April 22, 2021. Obesity contributes directly to numerous cardiovascular risk factors, including dyslipidemia, type 2 diabetes, hypertension, and sleep disorders. Obesity also leads to the development of cardiovascular disease and cardiovascular disease mortality independently of other cardiovascular risk factors. More recent data highlight abdominal obesity, as determined by waist circumference, as a cardiovascular disease risk marker that is independent of body mass index. There have also been significant advances in imaging modalities for characterizing body composition, including visceral adiposity. Studies that quantify fat depots, including ectopic fat, support excess visceral adiposity as an independent indicator of poor cardiovascular outcomes. Lifestyle modification and subsequent weight loss improve both metabolic syndrome and associated systemic inflammation and endothelial dysfunction. However, clinical trials of medical weight loss have not demonstrated a reduction in coronary artery disease rates. In contrast, prospective studies comparing patients undergoing bariatric surgery with nonsurgical patients with obesity have shown reduced coronary artery disease risk with surgery. This statement is intended to summarize the impact of obesity on the diagnosis, clinical management, and outcomes of atherosclerotic cardiovascular disease, heart failure, and arrhythmias, especially sudden cardiac death and atrial fibrillation. The influence of obesity on noninvasive and invasive diagnostic procedures for coronary artery disease is evaluated as well. Moreover, the new document encompasses a review of the impact of obesity on cardiac function and outcomes related to heart failure with reduced and preserved ejection fraction including the so called "obesity paradox". Finally, the authors describe the effects of lifestyle and surgical weight loss interventions on outcomes related to coronary artery disease, heart failure, and atrial fibrillation.