The win gives Clinton and Trump edge over their rivals Bernie Sanders and Ted Cruz and solidify their frontrunner status after a series of losses recently. It also resoundingly answers questions about their command of the race.
Trump's win means he could sweep the state's 95 delegates and position himself to win the Republican nomination without going through a contested convention in July.
Clinton's win could blunt Sanders' momentum once and for all and leave Sanders with a tough decision on how to proceed as she extends her overwhelming lead in the Democratic race.
Calling out Trump and Cruz for their remarks against Muslims and women, she said, "Donald Trump and Ted Cruz have a vision for our country that's divisive and dangerous- rounding up immigrants or banning Muslims is just not who we are."
"Threatening to ban Muslims" and treating American-Muslims like "criminal" go against "everything America stands for."
In a passing reference to Sanders, Clinton said it was not enough to just diagnose the problem. "America is a problem-solving nation. We have set progressive goals for creating more jobs and providing dignity and pride," she said.
As polls closed, media reports said that controversial billionaire Trump, 69, and Clinton, 68, have won.
Clinton, who was senator of New York for eight years, was conformably ahead of Sanders, 74, winning 59.3 per cent of the votes so far, way ahead of 40.8 per cent votes won by Sanders.
"Thank you to all those who came out tonight in New York! Onward to five more states voting next week," he tweeted.
