Mayawati, head of India's most populous state, Uttar Pradesh, was described in the cables as "a first-rate egomaniac" who "is obsessed with becoming prime minister".
The 55-year-old Mayawati, who goes only by one name, has built a career on championing the cause of the untouchables, known as Dalits, who are among India's poorest and most deprived people.
But she has been criticised for corruption, throwing lavish celebrations and building parks with massive statues of Dalit leaders, including herself.
"When she needed new sandals, a jet flew empty to Mumbai to retrieve her preferred brand," according to a cable dated October 23, 2008. "She constructed a private road from her residence to her office, which is cleaned immediately after her multiple vehicle convoy reaches its destination."
Mayawati also employed food tasters to guard against poisoning, it said.
According to the same cable, one minister was forced to do sit-ups in front of Mayawati as a punishment for a minor offence, while those wanting to become election candidates for her party had to pay tens of thousands of dollars for the privilege.
A spokesperson for Mayawati said in a statement that "such exposes" do not carry any authenticity, but she did not mention WikiLeaks by name.
Supporters of Mayawati, a former teacher, say her acts fill them with a sense of pride and are a source of inspiration to the millions of Dalits who have traditionally been forbidden from displays of well-being.
At her birthday parties, top public figures, including police chiefs and politicians, are often seen feeding her cake. Mayawati kicked up a storm last year for receiving a garland of cash at a political party celebration.
The Congress party has been campaigning aggressively to try and wrest Uttar Pradesh from Mayawati's Bahujan Samaj Party (BSP), deploying its star campaigners such as party chief Sonia Gandhi and her son Rahul, to garner support.
Dislodging strong regional parties is seen as key to Congress' ability to push through painful structural economic and political reforms to modernise Asia's third largest economy in the years ahead.
India is awash with stories of corruption that have piled pressure especially on the federal coalition and sparked a wave of street protests demanding tougher laws.