The rapid worldwide rise in obesity rates over the past few decades imposes an urgent need to develop effective strategies for treating obesity and associated metabolic complications. Bariatric surgical procedures, such as Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), currently provide the most effective treatment for obesity and type 2 diabetes (T2D), as well as for non-alcoholic steatohepatitis (NASH). However, the underlying mechanisms of the beneficial effects of bariatric surgery remain elusive. Recent studies have identified bile acids as potential signaling molecules involved in the beneficial effects of bariatric surgery. This review focuses on the most recent studies on the roles of bile acids and bile acid receptors Farnesoid X receptor (FXR) and G protein-coupled bile acid receptor 5 (TGR5) in bariatric surgery. We also discuss the possibility of modulating bile acid signaling as a pharmacological therapeutic approach to treating obesity and its associated metabolic complications.