Trump defied protesters to make his highly anticipated but controversial appearance on the primetime TV comedy show.
Wearing a dark suit, white shirt and red tie, the bombastic Trump stepped on stage to cheers.
In a nearly five-minute opening monologue, that saw him flanked by two lookalikes, he insisted: "I am a nice guy."
"It's wonderful to be here. This is going to be something special," he said.
Trump, a billionaire real estate developer who has never held elected office, leads the polls for the Republican nomination for the White House.
He will be hoping his appearance on the show cements his status as frontrunner.
But the 69-year-old has courted controversy for his statements on immigration, promising that if he becomes president he will expel immigrants who are in the US illegally and build a wall along the border with Mexico.
He has also alleged that Mexico sends rapists and other criminals across the border.
That stance saw Latino community leaders hold a rally on Friday in Los Angeles calling on NBC Universal to drop Trump from Saturday Night Live.
There were more protests on Saturday in New York hours before the show was broadcast, with demonstrators marching to NBC's studio in Rockefeller Plaza.
- Agencies