Mailam Assembly constituency is located in Tamil Nadu and has witnessed electoral contests mainly between the Pattali Makkal Katchi (PMK), the Dravida Munnetra Kazhagam (DMK), and the All India Anna Dravida Munnetra Kazhagam (AIADMK).
In the 2021 Assembly elections, PMK candidate C. Sivakumar won the seat by securing 81,044 votes. He defeated DMK candidate Dr. R. Masilamani, who secured 78,814 votes. The margin of victory was 2,230 votes.
In the 2016 Assembly elections, Mailam constituency had a total of 2,11,372 electors, of which 1,71,211 valid votes were polled. DMK candidate R. Masilamani won the seat with 70,880 votes, defeating AIADMK candidate K. Annadurai, who secured 58,574 votes. The margin of victory was 12,306 votes.
In the 2011 Assembly elections, the constituency had 1,83,634 electors and recorded 1,51,434 valid votes. AIADMK candidate P. Nagarajan won the seat with 81,656 votes, defeating PMK candidate R. Prakash, who secured 61,575 votes. The margin of victory stood at 20,081 votes.