“Quaden, you are stronger than you know, mate,” Jackman said on Twitter.
“Everyone, let’s just please be kind to each other. Bullying is not OK, period.
“Life is hard enough.”
Williams, who like Quaden has dwarfism, has raised more than $100,000 on GoFundMe after viewing a video of the nine-year-old distraught after suffering bullying at his Brisbane school.
“This isn’t just for Quaden, this is for anyone who has been bullied in their lives and told they weren’t good enough,” he said.
“Let’s show Quaden and others, that there is good in the world and they are worthy of it.”
Williams says the money will be used to pay for flights, accommodation, meals and tickets to Disneyland near Los Angeles.
Leftover money will be donated to anti-bullying organisations.
Quaden is the face of Stand Tall 4 Dwarfism, which his mother Yarraka Bayles set up to raise awareness and fight against bullying.
“Brad Williams you’re an absolute legend,” a post to the Facebook page of charity Stand Tall 4 Dwarfism read.
“We can’t wait to meet you in America. Thank you so much.”
Yarraka, who posted the video on Facebook this week, said in a statement she was overwhelmed by the support.
“Thank everyone for the overwhelming show of love and support from so many people from all around the world,” she said.
“Quaden’s feeling the love and now he needs a good rest.”
She also said she would be meeting with “appropriate people in power” to discuss the bullying issue.
The NRL Indigenous All-Stars team uploaded a video message for Quaden, including an offer to lead the team out in Saturday night’s game on the Gold Coast.
This article first appeared on 7News and has been republished here with permission.