He was elected to the Lok Sabha for the first time in 1989 and thereafter he won consecutively in the 1991, 1996 and 1999 General Elections to the Lok Sabha from Adoor constituency for four straight terms.
However he was defeated in the 1998 and 2004 general elections.
He continued to win in 2009 Indian general election, 2014 Indian general election, 2019 Indian general election and 2024 Indian general election from Mavelikara Lok Sabha constituency[10] and is currently the longest serving Lok Sabha MP as he has remained MP for 29 years, winning the elections 8 times. The position of pro tem speaker, assigned for administering the oath taking ceremony of the elected MPs, is traditionally given to the senior most member. However, this tradition was broken in 2024 after Bhartruhari Mahtab was elected as pro tem speaker. In response, the INDIA alliance nominated K. Suresh as candidate for post of speaker, triggering an election for the post for the first time since independence.
^"NDA candidate Om Birla elected Speaker of Lok Sabha for 2nd consecutive term". Mathrubhumi. 26 June 2024. Retrieved 26 June 2024. New Delhi: Om Birla, the National Democratic Alliance (NDA) candidate and Member of Parliament from Kota, Rajasthan, was elected as the Speaker of the 18th Lok Sabha on Wednesday. The motion, moved by Prime Minister Narendra Modi and seconded by Defence Minister Rajnath Singh, was adopted through a voice vote amidst resounding 'Ayes' and 'Noes' echoing in the house. Pro-tem Speaker Bhartruhari Mahtab officially declared Om Birla as the Speaker of the lower house. Interestingly, the opposition, which had nominated K Suresh as the candidate for the INDIA bloc, chose not to press for a division vote.