V. S. Sivakumar started his political career through the Kerala Students Union (KSU) in 1978 and rose through the Youth Congress.

He was the elected Member of Parliament in the 13th Lok Sabha representing Thiruvananthapuram Parliamentary Constituency.

But in the 14th Lok Sabha elections in 2004 and by-election in 2005, he tasted defeat against P. K. Vasudevan Nair and Pannyan Raveendran of CPI, respectively, from the Thiruvananthapuram Constituency.

He emerged victorious against the former Minister V. Surendran Pillai of Kerala Congress (Anti-merger Group) by a margin of 5352 votes.

He was booked by Vigilance and Anti-Corruption Bureau (VACB) of Kerala on 27 February 2020 for illegally acquiring money via his close associates between 2011 and 2016.