His private jet touched down at Prestwick airport last night and he arrived at the hotel and golf course in Ayrshire a short time later.
He confirmed last month he had purchased the entire complex from Dubai-based group Leisurecorp for an undisclosed sum. The course will continue to be managed by Starwood Hotels & Resorts.
Turnberry is the only course in the Open Championship rota to be owned privately. Mr Trump has ambitions to host the Open at his other course in Aberdeenshire.
In a statement in April, Mr Trump said: “I intend to invest many millions of dollars in order to bring the hotel to the highest levels of luxury.
“When completed, I believe that the Turnberry Hotel will be the finest and most luxurious hotel in all of Europe.”
The billionaire New Yorker has said that he plans to establish a golf circuit involving the Doonbeg course in the west of Ireland, the Open Championship course at Turnberry and his resort on the Menie Estate in Aberdeenshire, creating what he calls the “Trump Triangle”.
He has also announced he will invest up to £36 million in the storm-ravaged County Clare course.