He had been receiving “critical care” from medics in Scotland after falling ill while carrying out his duty to protect the president on Sunday, but died on Tuesday morning surrounded by family members.
In a statement, the secret service said it was “with great sadness and regret” that they shared news of his death, describing the man – an agent of 19 years’ experience – as a “dedicated professional of the highest order”.
“The secret service thanks the medical personnel in Scotland, in addition to the members of the White House Medical Unit and Police Scotland, who provided exceptional care and support for a member of our family,” it added.
No further details have been released, including his name, as the service seeks to give his family privacy and time to inform others of his death.
Mr Trump was at Turnberry to bring the curtain down on his controversial UK trip, before heading to Helsinki for a heavily criticised summit with Russian President Vladimir Putin.
The president faced a hostile reception while in Scotland, with protests headlined by a stunt on Friday night in which a man flew above the Turnberry Hotel using a paraglider and unfurled a banner reading “Trump Well Below Par”.
He was later arrested and charged after police said he had breached a no-fly zone and committed a criminal offence, but has been released pending further enquiries.
More demonstrations followed when Mr Trump took to the course on Saturday, with some taking to a nearby beach and hills overlooking the greens to chant: “No Trump, no KKK, no racist USA.”
Mr Trump appeared non-fussed as he drove his buggy from hole to hole sporting a USA baseball cap, as other protests took place in Glasgow and outside the Scottish parliament building in Edinburgh, which featured the infamous giant baby blimp that debuted in London last week.