Yaacob made his political debut in the 1997 general election as part of the five-member PAP team contesting in Jalan Besar GRC and won.

[7] During the 2006 general election, Yaacob was part of the five-member PAP team contesting in Jalan Besar GRC and won 69.26% of the vote against the Singapore Democratic Alliance.

During the 2011 general election, Yaacob was part of the four-member PAP team contesting Moulmein–Kallang GRC and won 58.55% of the vote against the Workers' Party.

[6] During the 2015 general election, Yaacob was part of the four-member PAP team contesting in Jalan Besar GRC and won 67.75% of the vote against the Workers' Party.

He is currently a Professor in Practice at the Lee Kuan Yew School of Public Policy at the National University of Singapore, and also an Advisor to the Office of the President of the Singapore Institute of Technology (SIT) and the founding Director of the Community Leadership and Social Innovation Centre (CLASIC) at SIT.

[10] Yaacob has been active in community service since his school days and has been involved with the Association of Muslim Professionals, Jamiyah, Majlis Ugama Islam Singapura and the Nature Society.

[11] Questions arose in regards to his son's citizenship and if he would serve National Service were raised when a leaked US diplomatic cable from WikiLeaks stated the minister's two children as US citizens.