In the 2018 Penang state election, Kumaresan was selected to contest the Batu Uban state seat. He was elected to the
Penang State Legislative Assembly as the
Batu Uban MLA for the first term after defeating H'ng Chee Wey of
BN, Vikneswaran Muniandy of
PAS, Teoh Kok Siang of
MUP, and Teoh Kean Liang of
PFP by a majority of 17,273 votes. In March 2021, he lodged a police report after a social media user threatened to kill him, claiming that Kumaresan and his party were not doing enough to help the people. Kumaresan was nominated to defend his seat in the
2023 Penang state election. He was elected for a second term after defeating Mok Kok On of
PN and Lee Kim Noor of
MUDA. He had a slightly reduced majority of 16,708. In May 2025, he was vocal about his support for former MP
Nurul Izzah Anwar to take over as PKR deputy president from incumbent
Rafizi Ramli. The next year Kumaresan called for Rafizi to quit the party, saying that the defeated former leader had become arrogant and was undermining the party from within. == Election result ==