Balram Halwai is the White Tiger of the book's title - a title he earns by virtue of being deemed the smartest boy in his village, a community deep in the "Darkness" of rural India. Balram is the son of a rickshaw-puller; his family is too poor for him to be able to finish school, and instead he has to work in a teashop, breaking coals and wiping tables. Through these experiences, Balram learns much about the world and later states that the streets of India provided him with all the education he needed. Later, Balram gets his break when a rich man hires him as a chauffeur, and takes him to live in Delhi. The city is a revelation. As he drives his master to shopping malls and call centers, Balram becomes increasingly aware of immense wealth and opportunity all around him, while knowing that he will never be able to gain access to that world. As Balram broods over his situation, he realizes that there is only one way he can become part of this glamorous new India.

The novel takes the form of a series of letters written late at night by Balram to Wen Jiabao, the Premier of the State Council of the People's Republic of China. In the letters, Balram describes his rise from lowly origins to his current position as an entrepreneur in Bangalore, as well as his views on India's caste system and its political corruption.