Teo first stepped into the political arena in the 2001 general election, contesting as one of five members representing the Singapore Democratic Alliance (SDA) together with Yip Yew Weng, Christopher Neo, Foo Kok Wah and Abdul Rahim bin Osman in Tampines GRC against the team from the People's Action Party (PAP) represented by Mah Bow Tan, Yatiman bin Yusof, Ong Kian Min, Sin Boon Ann and Irene Ng.