Writing on Facebook on Tuesday, the 42-year-old actor said: "There is no excuse for sexual harassment or sexual assault - no matter who you are and no matter what profession. I applaud the strength and courage of the women who came forward and made their voices heard."
Leonardo's comments come after it was previously reported that Harvey had stepped down from positions in a number of charitable organisations, including the Leonardo DiCaprio Foundation, which was set up by the star to help fund initiatives that protect vulnerable wildlife from extinction.
Harvey has also reportedly resigned from amfAR, the Lebron James Family Foundation, Oceana and UNICEF following the harassment claims, whilst anti-poverty charity the Robin Hood Foundation has confirmed news of his resignation.
On top of his charity resignations, Harvey has also been fired from his own Weinstein Company, and had his BAFTA membership suspended.
In the wake of the scandal, Weinstein - who has denied many of the allegations against him - is believed to have checked into rehab, and his wife Georgina Chapman has left him, while he has also been slammed by big names in Hollywood, including Jennifer Lawrence, Meryl Streep, Kate Winslet, George Clooney, Angelina Jolie, and Dame Judi Dench.