Hollywood actors and music stars, from Lena Dunham to Moby, have signed a petition against what they say is the "hateful ideology" of Republican White House hopeful Donald Trump.

"We are a coalition of artists who, today, are joining millions of Americans in our commitment to defeat the presumptive Republican nominee for president, Donald Trump," the online pledge reads.

"We believe it is our responsibility to use our platforms to bring attention to the dangers of a Trump presidency, and to the real and present threats of his candidacy."

Among the hundred stars on board include actors Kerry Washington, Julianne Moore, Patricia Arquette, Jane Fonda and Woody Harrelson, and music stars Russell Simmons, Michael Stipe and DJ Spooky.

Keen to throw a spotlight on potential threats posed by Trump, they warned that the billionaire real estate mogul "wants to take our country back to a time when fear excused violence, when greed fueled discrimination, and when the state wrote prejudice against marginalized communities into law."

US voters, the group said, should "use the power of our voice and the power of our vote to defeat Donald Trump and the hateful ideology he represents."

Americans will vote for president on November 8.