Sunil Kumar started his political career as a leader of the student wing of the RSS, the Akhil Bharatiya Vidyarthi Parishad.
[2] Kumar lost the seat to H. Gopal Bhandary in the 2008 Karnataka Legislative Assembly election by a narrow margin of 1537 votes.
In November 2020, he was appointed Co-incharge of BJP Kerala by party president Jagat Prakash Nadda.
When BJP formed government under B.S.Yediyurappa in 2019, it was highly expected that Sunil Kumar will be made cabinet minister but his name was missing.
[4] He was re-elected as the MLA from Karkala for the fourth time in May 2023, defeating Uday Shetty of the Indian National Congress (INC) with a lead of 4,602 votes.