Police said on Monday the charges related to a "violent call to action" on social media, calling for protesters to gather at a beach in Sydney's south later in the week.
Investigators became aware of the posts the day after the Bondi massacre, during which 15 people were killed by two gunmen apparently inspired by Islamic State ideology.
A post circulating online had called for "wog" and "Middle East" bashing at Cronulla beach on Sunday, 20 years since the infamous race-fuelled riots at the same location.
More than 100 people were arrested during the December 11, 2005 riots, which followed a text message circulating among locals that called on "Aussies" to show "Lebs and wogs" they weren't welcome after growing tensions at the beach.
Police arrested a 20-year-old man at Narara, on the NSW Central Coast, about 1.40pm on Sunday over the social media post.
He has since been charged with using a carriage service to menace, harass, offend and publicly threaten violence on grounds of race or religion.
The man has been denied bail and will appear in court on Monday.
Police said the organiser of the event did not obtain authorisation for the rally, adding that anyone considering violence, retribution or vigilante behaviour could expect a swift and decisive response from authorities.
"While the NSW Police Force recognises people may want to protest due to recent events both here and overseas, we are asking the community to choose other ways to come together peacefully," police said in a statement.
NSW Premier Chris Minns previously said the planned Cronulla rally would be met with the full force of the law and there would be no tolerance for any acts of retribution following the Bondi massacre.
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