Simon John Birmingham (born 14 June 1974) is a former Australian politician who was a Senator for South Australia between May 2007 to January 2025.

On 30 October 2020, Birmingham was sworn in as Minister for Finance and became Leader of the Government in the Senate following the resignation of Mathias Cormann.

Early in 2000 Birmingham moved to Canberra to become the national manager of public affairs for the Australian Hotels Association.

[8] In late 2001, Birmingham was appointed chief of staff to the South Australian state minister for tourism and innovation, Martin Hamilton-Smith.

Following a change of government in 2002, Birmingham began work with the Winemakers' Federation of Australia where he remained until his appointment to the Senate in 2007.

[9] At the age of 29, Birmingham won Liberal Party preselection for the marginal seat of Hindmarsh at the 2004 federal election following the retirement of sitting member Chris Gallus.

[5] According to Andrew Tillett, writing in The Australian Financial Review in August 2019, the retirement of Christopher Pyne saw Birmingham "assume the mantle as the most senior moderate" in the party.

[30] In 2021, Nine Entertainment journalist James Massola identified Birmingham as the leader of the party's "Moderate/Modern Liberal" faction in the Morrison government.

[31] Birmingham is married to his former campaign manager Courtney Morcombe, who was the chief of staff to former South Australian premier Steven Marshall.