Patterson was elected as a Councillor for the
City of Holdfast Bay in November 2010, and went on to become Deputy Mayor during his term. He became Mayor in November 2014, defeating incumbent Ken Rollond. In April 2017, he defeated the sitting member,
Duncan McFetridge, in
Liberal Party preselection for the
electoral district of Morphett at the
2018 state election, and was subsequently elected. While he only won 41 percent of the primary vote, McFetridge's preferences flowed overwhelmingly to him, allowing him to easily reclaim the seat for the Liberals. Patterson has previously served as the Presiding Member of the
South Australian House of Assembly Environment, Resources and Development Committee, and the Parliamentary Committee on Occupational Safety, Rehabilitation and Compensation. He has also previously served as a Member of the Economics and Finance Committee, the Public Works Committee, and the Joint Committee on Valuation Policies and Charges on Retirement Villages. On 29 July 2020, Patterson was appointed as Minister for Trade and Investment, replacing
David Ridgway in a cabinet reshuffle. On 21 April 2022, Patterson was appointed as the Shadow Minister for Energy and Net Zero, Shadow Minister for Mining and Shadow Minister for Defence and Space Industries. Patterson was defeated at the
2026 state election by
Labor candidate
Toby Priest. ==Personal life==