Rex Lyall Patrick (born 8 May 1967) is an Australian politician who served as a Senator for South Australia from November 2017 until June 2022.

Before entering politics, Patrick served as a submariner in the Royal Australian Navy, then was a businessman and senior business executive officer.

[8] On inheriting the Quantum Ark Technologies' files in 2013, Patrick discovered a mass data breach of classified documents from the French manufacturer DCNS related to the new Indian Navy's Scorpène submarines.

Premier Jay Weatherill revealed that an NXT Senate candidate from the 2016 election, Tim Storer, had "assert[ed] rights" to the vacancy.

[23] In December 2017, Patrick informed the Turnbull Government that NXT would suspend negotiations on welfare reform because a minister had failed to answer "reasonable questions".

[24] Notably Patrick supported the blocked a vote in the Senate that would've seen an inquiry into the Liberal and National Party government "Grass-gate" scandal.

Labor was pursuing the Energy Minister Angus Taylor over his interest in a family company linked to an investigation into alleged illegal land clearing.

[28] Patrick pulled a stunt in the federal Senate Chamber to push his view that submarine jobs would be lost to Western Australia.

"[29] In August 2020, Patrick split from the Centre Alliance, arguing that standing as an independent would improve his chances for re-election at the next federal election.

[30] His Centre Alliance Senate colleague Stirling Griff regarded the move as akin to removing "a powerful voting bloc that has achieved a remarkable amount for South Australia".

[37] He lost to Jane Lomax-Smith by 52 votes, prompting Patrick to appeal the result due to the small margin and potential voter fraud.