| Honorific-Prefix: | The Honourable |
| Stephen Mullighan | |
| Honorific-Suffix: | MP |
| Office: | Treasurer of South Australia |
| Premier: | Peter Malinauskas |
| Term Start: | 21 March 2022 |
| Predecessor: | Rob Lucas |
| Office1: | Minister for Transport and Infrastructure |
| Premier1: | Jay Weatherill |
| Term Start1: | 26 March 2014 |
| Term End1: | 18 March 2018 |
| Predecessor1: | Tom Koutsantonis |
| Constituency Am4: | Lee |
| Assembly4: | South Australian House of |
| Term Start4: | 15 March 2014 |
| Predecessor4: | Michael Wright |
| Birth Name: | Stephen Campbell Mullighan |
| Birth Date: | [1] |
| Nationality: | Australian |
| Party: | Australian Labor Party (SA) |
| Spouse: | Antonia Mullighan |
| Relations: | Ted Mullighan (father) |
| Alma Mater: | University of Adelaide |
| Occupation: | Political staffer |
Stephen Campbell Mullighan is an Australian politician representing the South Australian House of Assembly seat of Lee for the South Australian Branch of the Australian Labor Party since the 2014 state election.[2] He has served as the Treasurer of South Australia in the Malinauskas government since 2022.
Mullighan served as Minister for Transport and Infrastructure and Minister for Housing and Urban Development in the Weatherill Labor cabinet.
He previously held the portfolios of Minister assisting the Minister for Planning and Minister assisting the Minister for Housing and Urban Development. Mullighan entered cabinet in March 2014 and remained there until the March 2018 election when his party lost office. He has held ministerial portfolio with responsibility for transport and infrastructure, and for housing and urban development.[3]
He is aligned with the Labor Right faction.[4]