The US president acknowledged demonstrators outside the South Ayrshire course as they shouted “no Trump” and “no racist USA”.
The president concludes his UK visit on Sunday, before travelling to Moscow for talks with Russian President Vladimir Putin.
Thousands marched to demonstrate against Mr Trump across Scotland on Saturday, with protests in Turnberry, Edinburgh and Aberdeenshire.
At Turnberry, protesters climbed a hill to ensure the president could see them as they shouted: “No Trump, no KKK, no racist USA.”
Wearing a white baseball cap with USA stitched on it, the president waved to the protesters, who stood behind a row of police officers on the outskirts of the luxury golf resort.
Little information was released about exactly how Mr Trump would be spending his time in Scotland, before he tweeted on Saturday afternoon: “I have arrived in Scotland and will be at Trump Turnberry for two days of meetings, calls and hopefully, some golf – my primary form of exercise!”
He added: “The weather is beautiful, and this place is incredible! Tomorrow I go to Helsinki for a Monday meeting with Vladimir Putin.”
Meanwhile at a LGBT Pride march in Glasgow, Scottish first minister Nicola Sturgeon said she had been a “wee bit tickled” by reports Mr Trump “hates her” and has been complaining about her to Theresa May.
Ms Sturgeon said: “I find it hard to believe that the president of the United States with all the big important issues that he has to deal with on a daily basis, finds the time to rant about me on the telephone to Theresa May.
“If it is true, I suppose I should take it as a compliment, I certainly don’t spend that much time talking about him.”
The protests across Scotland were peaceful and there were no arrests.
Assistant chief constable Mark Williams from Police Scotland said: “Around 2,000 people were in Glasgow and approximately 250 were in Dundee on Friday evening, a further 9,000 marched and took part in a rally in Edinburgh today.
“The detailed planning which took place in advance meant the events passed without incident and I would like to thank everyone who took part for their good behaviour.”
Police are investigating after a paraglider flew over Turnberry last night with a sign claiming the president is “well below par” shortly after Mr and Mrs Trump’s arrival at the resort.
As well as anti-Trump demonstrations, dozens of people attended a pro-Trump rally outside the US embassy in London, with signs that read “Make Britain great again”.
Those demonstrations coincided with a campaign to free former EDL leader Tommy Robinson from jail, who is serving time for contempt of court.