Obesity is a chronic disease and is an important risk factor for many obesity associated diseases, including type 2 diabetes, hypertension, obstructive sleep apnea, various cancers, dyslipidemia, and cardiovascular disease, and is a leading cause of mortality today. Metabolic and bariatric surgery (MBS) is a specialized field which focuses on surgeries and procedures aimed to induce weight loss and improve the chronic diseases linked with obesity, has been shown to be effective in this pursuit, and has become a mainstay of current-day obesity management. Bipolar disorder is a psychiatric disorder which is known to cause extreme mood swings resulting in episodes of mania and depression. Approximately 68% of patients diagnosed with bipolar disorder have been found to have concurrent obesity, a percentage that is significantly higher than the prevalence of obesity in the general population. This chapter examines different aspects of bariatric surgery and bipolar disorder as they relate with each other, including preoperative screening and selection, perioperative management, and postoperative outcomes with long-term management.