Singh's eldest son Ajeya Pratap lit the funeral pyre as family members, relatives, friends and admirers bade him a tearful adieu.
Union Ministers, including Ram Vilas Paswan and Subodh Kant Sahay, Uttar Congress president Rita Bahuguna Joshi and a host of other leaders attended the cremation near the holy Sangam.
Earlier, Samajwadi Party chief Mulayam Singh Yadav and Bihar Chief Minister Nitish Kumar were among a large number of people who visited Singh's residence here to have the last glimpse of the departed leader.
Singh, who dethroned late Rajiv Gandhi to form the first non-Congress coalition government at the Centre in 1989, died Thursday in the national capital.
Battling cancer for over 17 years, the 77-year-old leader had breathed his last in Apollo Hospital where he was admitted some six months ago.
People lined on both sides of the road as the funeral procession wound its way through different parts of the holy city.
Slogans eulogising the late leader rent the air as the flower-bedecked vehicle carrying the tricolour-draped body passed by.
The bugles sounded the last post and police and army personnel reversed arms as Singh's eldest son lit the pyre.