Sabarinadhan was born to former minister and speaker G. Karthikeyan and M. T. Sulekha in Thiruvananthapuram on 5 September 1983.

[3] Sabarinadhan is married to Divya S. Iyer,[4] a civil service officer, thus becoming the first MLA–IAS couple in Kerala.

[6] In 2015, Sabarinadhan contested the by-election from Aruvikkara constituency, which was vacated due to the death of his father.

[7][8][9] In the 2016 Kerala Legislative Assembly election, he was re-elected from Aruvikkara constituency.

[11] In the 2021 Kerala Legislative Assembly election, he lost to G. Steephen of the CPI(M) by 5046 votes.