Making a rare visit to the state, Gandhi shared the dais with the 105-year-old Siddaganga Math head Sri Sri Shivakumara Swami and praised his role in various fields including education.
The Swami has a vast following among Lingayats, a community that had distanced itself from the Congress ever since the unceremonious removal of a paralysed Veerendra Patil as Chief Minister in 1989 at the height of riots.
The community had ever since backed the BJP, which had its first government headed by B S Yeddyurappa, who is a Lingayat.
The function was marred by a woman in the audience showing black cloth to Gandhi on reservation issue.
Gandhi in her address hailed the "philanthropy, spirituality and social service" rendered by the Swami for the cause of humanity.
She said that nothing exemplifies India's diversity better than Karnataka, where people belonging to different regions, from different culture and speaking different languages, have lived together.