Sudeep was born to Sanjeev Manjappa and Saroja in Shimoga district of the erstwhile Mysore State (now Karnataka). He obtained his bachelor's degree in Industrial and production engineering from Dayananda Sagar College of Engineering, Bangalore. He was a University-level cricket player during the day and had also represented at the State-level in its Under-17 and Under-19 teams. Before taking up acting as a profession, Sudeep attended the Roshan Taneja School of Acting in Mumbai, where he overcame 'shyness'.
Sudeep is the captain of Karnataka Bulldozers cricket team that competes in the Celebrity Cricket League. He owns a film production company named Kiccha Creations and a few films have been produced under the banner, including the 2007 No 73, Shanthi Nivasa that stars Sudeep himself.
Sudeep met Priya Radhakrishnan, belonging to the Nair community of Kerala, in Bangalore, in 2000 and they married in 2001. Priya worked in an airline company and then in a bank, prior to their marriage. Their only child, Saanvi, was born in 2004. In 2013, Sudeep launched Stage 360°, an event management company, that his wife took active part in. On 11 September 2015, Sudeep announced that he and his wife decided to separate ending their 14-year marriage, citing "irreconcilable differences going on for some years". Sought under Section 13 (B) of the Hindu Marriage Act, the divorce was finalized by a family court of Bangalore on the same day. He was asked to pay a permanent alimony of ?19 crore (US$2.8 million) and to surrender the custody of his daughter to Priya.