He has been a member of the Victorian Legislative Council, representing the Northern Metropolitan Region, since November 2022.

[1][2] Following his election at the 2022 state election, in December that year, he was immediately elevated to the position of Shadow Cabinet Secretary in John Pesutto's shadow cabinet.

[3] On 31 August 2023, he was elected as the deputy leader of the party in the Legislative Council.

[4] In October the same year, after a shadow cabinet reshuffle, he was appointed as Shadow Minister for Home Ownership and Housing Affordability, and Shadow Minister for Outer Suburban Growth.

[5] Before entering parliament, Mulholland worked for the Institute of Public Affairs.