Siddaramaiah was born on August 3, 1947 in Mysuru, Karnataka. He is a member of the Kuruba community, which is a Scheduled Tribe in Karnataka. Siddaramaiah studied at the University of Mysore, where he received a Bachelor of Arts degree in economics.

Siddaramaiah was a member of various Janata Parivar factions before finally joining the Congress in 2006. Under the Janata Party and Chief Minister Ramakrishna Hegde, Siddaramaiah was appointed to his first government position in 1983. He became chairman of the erstwhile Kannada Watchdog Committee, to guard the interests of the Kannada language — a task he still considers close to his heart.

In 1996, Siddaramaiah became deputy CM under J H Patel, a post he held again in 2004 in a JD(S)-Congress coalition government. In 2006, however, Deve Gowda sacked him for floating a collective of backward castes, Dalits and minorities in the state called AHINDA, which was viewed as an anti-party activity.

Soon after, Siddaramaiah joined the Congress. In 2006, he won a bypoll from Chamundeshwari seat in his home district of Mysore by a narrow margin of 257 votes, against the combined might of the ruling JD(S)-BJP coalition.

A backward class leader with over five decades of political experience, Siddaramaiah, 75, is considered one of the three remaining mass leaders of Karnataka – alongside former prime minister H D Deve Gowda, 91, of the JD(S) and ex-CM B S Yediyurappa, 80, of the BJP.

As CM holding the Finance portfolio during his 2013-18 tenure, Siddaramaiah had implemented measures such as providing 7 kg of rice to members of BPL homes, setting up canteens selling food at low costs, allotment of substantial funds for free food grains and milk to the poor, and for schemes meant for backward classes, Dalits and minorities. Nearly 24% of the state budget was set aside annually for SC/ST communities.

Siddaramaiah has consciously projected an image of a rustic, down-to-earth politician who identifies with the problems of the downtrodden, including the Dalits.