A Gentleman: Sundar, Susheel, Risky is an action romantic drama. The story revolves around Gaurav (Siddharth Malhotra), a young man living in Miami, USA. He plans to marry and settle down with his girlfriend, Kavya (Jacqueline Fernandez). However, his life takes a turn when he visits Mumbai where he is mistaken for being Rishi Purohit, a spy, who looks exactly like him. His life is in danger as he unknowingly welcomes many enemies who were after Rishi and assuming him to be Rishi. What happens next, how will Gaurav get out of this mess?