Udhayanidhi is the son of politician M. K. Stalin and the grandson of M. Karunanidhi, a former Chief Minister of Tamil Nadu. Several of his relatives have been actively involved in politics and Tamil cinema since the 1960s, while his cousins Arulnithi and Dayanidhi Azhagiri are also active in films as an actor and producer, respectively. Udhayanidhi is married to Kiruthiga, who heads the lifestyle magazine Inbox 1305; while, she also directed the film Vanakkam Chennai (2013) for Red Giant Movies. He started his first film production through the film Kuruvi starring Vijay. Then he produced the films Aadhavan starring Suriya, Manmadan Ambu starring Kamal Hassan, 7aam Arivu starring Suriya, Neerparavai starring Vishnu Vishal and Oru Kal Oru Kannadi in which he himself acted in the lead role.