Richard Donald Marles (born 13 July 1967) is an Australian politician and lawyer who has served as the 19th deputy prime minister of Australia and the minister for defence since 2022. He has been the deputy leader of the Labor Party since 2019 and the member of parliament (MP) for the Victorian division of Corio since 2007.

Marles grew up in Geelong, Victoria, and is a lawyer by profession. He was assistant secretary of the Australian Council of Trade Unions from 2000 to 2007. He was elected to the House of Representatives at the 2007 federal election, after defeating incumbent Labor MP Gavan O'Connor for preselection in the seat of Corio. Marles was made a parliamentary secretary in 2009 and briefly served as Minister for Trade in 2013, having supported Kevin Rudd's return as prime minister. He was appointed to shadow cabinet after the ALP's defeat at the 2013 election and became a senior figure in the Labor Right faction.

Marles was elected deputy leader under Anthony Albanese after the 2019 election, becoming deputy opposition leader. Following the ALP's victory at the 2022 election he was appointed Deputy Prime Minister and Defence Minister.

Marles was born on 13 July 1967 in Geelong, Victoria. He is the son of Donald Marles, a former headmaster of Trinity Grammar School, and Fay Marles (née Pearce), Victoria's first Equal Opportunity Commissioner and later Chancellor of the University of Melbourne.

Marles was educated at Geelong Grammar School, where his father had been a house master, and the University of Melbourne, where he was a resident of Ormond College. He joined the Melbourne University Labor Club in his first week at university and served as president of the Melbourne University Student Union in 1988. He was also the general secretary of the National Union of Students in 1989. He graduated with a Bachelor of Science and Bachelor of Laws with Honours and began his career as a solicitor with Melbourne industrial law firm Slater and Gordon. In 1994, he became legal officer for the Transport Workers Union (TWU) and was elected TWU national assistant secretary four years later. In 2000, he joined Australia's peak union body, the Australian Council of Trade Unions, as assistant secretary, remaining in the position until 2007.

In March 2006, Marles nominated for Labor preselection against the sitting member for Corio, Gavan O'Connor, as part of a challenge to several sitting members organised by the right-wing Labor Unity faction of the party. In the local ballot Marles polled 57% of the vote, and his endorsement was then confirmed by the party's public office selection committee.

Marles was elected member for Corio on 24 November 2007 in the election that returned the Labor Party to office under the leadership of Kevin Rudd. From February 2008 to June 2009 he was chair of the House of Representatives Standing Committee on Aboriginal and Torres Strait Islander Affairs.

In June 2009 Marles was appointed Parliamentary Secretary for Innovation and Industry. He retained his seat in the 2010 election and was sworn in as Parliamentary Secretary for Pacific Island Affairs in the First Gillard Ministry on 14 September 2010. In July 2011, Marles became the first Australian member of parliament to visit Wallis and Futuna. Marles arrived in Wallis and Futuna to attend a ceremony with King Kapiliele Faupala in Mata-Utu marking the 50th anniversary of the islands' status as a French Overseas collectivity. Marles had previously visited New Caledonia in October 2010 and French Polynesia in March 2011.