He was elected to the Victorian Legislative Assembly as a Liberal Party member for Polwarth, at a by-election held October 31st, 2015.
[citation needed] Riordan experienced defeat in pre-selection again in 2010 before being successful in 2015, and was subsequently re-elected at the 2018 state election.
Riordan was appointed Assistant Shadow Minister for Agriculture and Regional Development and Deputy Chair of The Public Accounts and Estimates Committee.
[2][3][4][5] Marquee issues for Riordan include wire rope barriers on county roads, and their effectiveness as a notable and important life-saving measure.
came under fire for his comments after the death of a truck driver in Clifton Springs[7] where he was accused of using a fatality for political gain.