North-east Tory MP David Duguid has been brought back into UK’s Scotland Office by Liz Truss.
Mr Duguid will work for cabinet minister Alister Jack as parliamentary under-secretary of state, a position he held until last September when he became a trade envoy.
The Banff and Buchan MP repeatedly showed loyalty to Boris Johnson when he was in office and backed him in a House of Commons confidence vote.
But he finally turned against the ex-Tory leader in July when dozens of ministerial resignations eventually forced him out as prime minister.
He was the final Scottish Tory MP to remove his support for Mr Johnson.
After his appointment, Mr Duguid said: “I am honoured to have been appointed as a Scotland Office minister.
“I look forward to working with the Scottish Secretary and ministerial colleagues across the UK Government to deliver our ambitious programme for the people of Scotland.”
Tory chief Ms Truss has given key cabinet posts to some ministers who backed her predecessor until the end, including Jacob Rees-Mogg.
Key allies of defeated rival candidate Rishi Sunak have largely been frozen out of her government.
In his new role, Mr Duguid can be expected to continue lobbying for a green freeport bid from Aberdeen and Peterhead to be accepted.
The UK Government has confirmed two of the special economic zones will be launched in Scotland and backers of the north-east bid hope it can bring thousands of jobs to the area.
Mr Duguid sparked anger among environmentalists last year when he claimed it would be better to extract oil and leave it unused rather than importing supplies from abroad.
His party leader Ms Truss wants to ramp up oil and gas production in the North Sea in response to the energy crisis despite SNP opposition.
Mr Duguid argued domestic fossil fuels supplies were better since the industry could help support British workers.