Section 18C of the Racial Discrimination Act makes it unlawful to offend, insult, humiliate or intimidate someone because of their race, colour or national or ethnic origin.
Senator Hanson recently failed to quash a court ruling that she made a racist remark online.
She was found in 2024 to have racially vilified deputy Greens leader Mehreen Faruqi by telling her in a tweet to "piss off back to Pakistan".
In his Federal Court decision in 2024, Justice Angus Stewart ruled the tweet was "seriously offensive" and a "strong form of racism".
Senator Hanson launched an appeal but it was dismissed by the Full Court of the Federal Court on July 27.
On Saturday she said in a statement the case was "bigger than her and bigger than one tweet".
"I'm taking this fight to the High Court for every Australian who feels they are being silenced and (have) to keep their opinions to themselves.
"Too many Australians are afraid to speak honestly about immigration, race, religion, Indigenous policy and other important issues because they worry they will be called racist, dragged through a complaints process or taken to court."
The government should never choose what Australians are allowed to say and speaking plainly about political issues should not land people in court, Senator Hanson said.
The tweet that landed her in trouble was in response to a social media post from Senator Faruqi on the day of Queen Elizabeth's death in which she offered condolences to those who knew the monarch.
But she added she could not mourn the passing of the leader of a "racist empire built on stolen lives, land and wealth of colonised peoples".
Senator Hanson retorted she was appalled and disgusted by the comments.
"When you immigrated to Australia you took every advantage of this country," she wrote.
"It's clear you're not happy, so pack your bags and piss off back to Pakistan."
On a recent trip to Europe Senator Hanson met with anti-immigration activist and convicted criminal Tommy Robinson and told a conservative conference Australia had been flooded with migrants.
