He was a Liberal Democratic Party (LDP) member of the Victorian Legislative Council between 2018 and 2022, representing Northern Victoria Region.

Before his election to parliament, he served as a councillor on the City of Wodonga, previously contesting the Division of Indi for the LDP in the 2016 Australian federal election, as well as the seats of Eden-Monaro in 2007 and Riverina in 2010.

He had previously contested Eden-Monaro as a member of the Outdoor Recreation Party in 2004.

In 2022, Quilty was the only member of the Victorian parliament to oppose a bill that would ban the public display of the Nazi swastikas.

[2][3] Prior to entering politics, Quilty was a farmer and an accountant.