Duluk was born in the Victorian city of Mildura, and is descended from post-war migrants from Poland.^[3] He was raised in Adelaide and educated at Marryatville High School, then graduated with a Bachelor of Commerce (Accounting) from the University of Adelaide, working as an accountant in the banking industry. He was state president of the South Australian Young Liberal Movement.^[4]

Duluk won Davenport at a 2015 by-election, despite a five percent two-party-preferred swing against him, which turned the historically safe Liberal seat of Davenport in to a marginal one for the first time.^[5] After a redistribution transferred most of his constituents to the neighbouring seat of Waite, Duluk opted to contest Waite and won.

On the first sitting day of 2020, Duluk expressed regret for several alleged instances of inappropriate behaviour at a parliamentary Christmas party in December 2019. The Speaker, Vincent Tarzia, commissioned a private investigator to produce a report into Duluk's conduct, which allegedly included slapping SA Best MLC Connie Bonaros on the backside and making racist and homophobic comments to other MPs.^[6] A week later, after police confirmed Duluk had been reported for "basic assault" over the incident concerning Bonaros, the South Australian premier, Steven Marshall, said that Duluk could no longer attend meetings of the Parliamentary Liberal Party. Duluk subsequently announced that he would take leave from parliament and suspend his membership of the party while the matter was under investigation.^[7] In April, he was summonsed to appear in the Adelaide Magistrates Court on 6 October 2020. He apologised in parliament for his behaviour and said he was seeking help in combating an alcohol problem.^[8] In October, Duluk's lawyers asked the court for access to a private investigator's report to the speaker of the House of Representatives. The matter returned to court in December 2020 when the new Speaker of the House claimed that the draft report was covered by parliamentary privilege.^[9] On 25 August 2021 the court found him not guilty of assault, but magistrate John Wells said he "behaved like a drunken pest" and his behaviour was "entitled, uncouth and disrespectful". He was advised by the magistrate that "Your behaviour towards Ms Bonaros … was rude, unpleasant, insensitive and disrespectful. You owe her an apology."^[10] On 8 September 2021 new allegations were raised against Duluk relating to his behaviour at the 2019 Christmas party by Greens MLC Tammy Franks in an address to the legislative assembly. Chief among these were allegations that Duluk had made sexual remarks about numerous women present, as well as homophobic comments directed at a male parliamentary staff member. Additionally, Duluk was accused of remarking that an Indigenous MP was "not a real Aboriginal."^[11][12] On 9 September the following day Duluk announced he would be running as an Independent at the upcoming state election.^{[13] [14]}

• Official website
• "Duluk, Sam". Former members of the Parliament of South Australia. Retrieved 19 August 2022.