Sunil Mittal belongs to an Indian ethnic 'Baniya' family. He has two brothers, Rakesh and Rajan who helped him built Bharti Group into India's largest mobile phone operator in just ten years. His father, Sat Paul Mittal, former Member of Paarliament was always in the public eye. Sunil did not want to follow his father's footsteps and started a business at a very early age. Initially he joined the Wyanberg Allen School in Mussoorie but later he attended Scindhia School at Gwalior. In 1976, Sunil graduated with a Bachelors of Arts and Science, from the Punjab University, Chandigarh.
From a very early age Sunil started a business with his two brothers and a friend in 1976. He started his career with selling bicycle parts, and later saw an opportunity in telecom in the mid-1990s as India opened up to the private sector. Bharti began with a licence to operate a mobile network in Delhi. And eventually expanded Bharti's coverage nationwide, building the leading mobile operator with control of a quarter of the world's fastest-growing mobile market.