Former navy submariner, businessman and political adviser, Rex Patrick is set to become South Australia's newest senator.
Mr Patrick will replace Nick Xenophon who has quit federal parliament to stand for a seat in the South Australian lower house at the next state election in March.
His appointment was approved by a joint sitting of the SA parliament on Tuesday and he will be sworn in on Wednesday.
He comes to the job after working as an advisor to Mr Xenophon for two years and plans to focus on areas such as defence, the manufacturing sector, energy prices and the Murray-Darling Basin.
The 50-year-old was born in New Zealand but came to Australia with his family as a seven-year-old.
He says he's renounced his New Zealand citizenship to ensure he is eligible to take up the Senate vacancy.