Obesity has reached global epidemic proportions and is associated with numerous comorbidities such as hypertension (HTN), type 2 diabetes mellitus, dyslipidemia, certain cancers, and chronic kidney disease (CKD). Obesity, via its direct maladaptive effects on cardiac structure and through its impact on conventional risk factors, is strongly associated with cardiovascular (CV) diseases such as heart failure (HF) and coronary heart disease (CHD). Despite these adverse associations, numerous studies indicate an "obesity paradox" in that being overweight or obese is associated with a favorable prognosis in many patients with established CV disease, particularly in patients with HTN, HF, and CHD. This review summarizes the adverse effects of obesity on CV disease risk factors and its role in the genesis of HTN, HF, CHD, and the obesity paradox. It concludes with a discussion on the potential benefits of weight loss in these patient populations.