The billionaire now has three caucus wins in a row, after victories in New Hampshire and South Carolina.
Senators Marco Rubio and Ted Cruz, who have been trading barbs this week, came second and third respectively.
An angry electorate hungry for a political outsider in the White House catapulted Trump to his third straight win in the GOP primary race as the billionaire mogul used visceral rhetoric to tap into anxieties about the economy, terrorism and illegal immigration.
In his victory speech, Mr Trump told a roaring crowd: “We’re winning, winning, winning the country, and soon the country is going to start winning, winning, winning.”
He also celebrated getting the support of the “poorly educated” and Latinos. Some 45% of Nevada’s Republican voters of Latino origin backed Mr Trump, according to entrance polls.
Nevada, typically a swing state with a substantial Latino population, is crucial to the election process. Hillary Clinton won the state on Saturday in the Democratic race.
Watch his victory speech below