Heath Duke, 20, appeared in Adelaide Magistrates Court on Monday after admitting 16 counts of displaying a Nazi symbol and breaching bail.
He was initially reported over 97 social media posts between February and April that featured Nazi propaganda, Hitler speeches, anti-Semitic content, and material glorifying Hitler and National Socialism.
Duke was charged with 13 counts of displaying a Nazi symbol, which were representative of the 97 posts.
A prosecutor told the court that on May 25, Duke went to a McDonald's outlet in Collinswood where he was employed, dressed in a Nazi-style uniform that displayed a swastika and a swastika pin attached to the tunic.
He told a witness "we all know something had to be done about them", the prosecutor said.
Duke was subsequently sacked.
When police went to his home on June 3, they seized the uniform and a large Nazi flag on display.
While on bail, Duke breached his conditions by posting further Nazi-related material online.
The maximum penalty for each offence under South Australian laws banning the display of Nazi symbols is 12 months in prison or a $20,000 fine.
Magistrate Koula Kossiavelos said a pre-sentence report showed Duke had diagnoses of autism, attention deficit disorder, and oppositional defiant disorder, and had a "significant fixation" with extreme right-wing beliefs.
"You have had significant isolation and loneliness, and you have decided that you identify with Thomas Sewell and have a strong desire to relate to the National Socialist movement," she said.
"For the Jewish community in Australia, this would be a very sad case to see a young man who's 20 years of age and is fixated on issues that have been deeply felt for them."
Duke's lawyer said his client, who had two black eyes, was very vulnerable and "he's had a very difficult time in custody".
Duke had spent a total of 12 days in custody. The prosecutor asked that convictions be recorded but was not opposed to a suspended jail term.
"I consider that (convictions) would be harsh in the circumstances, especially where you have underlying disability that has contributed to this behaviour," Ms Kossiavelos told Duke.
She noted he was a young man from "a good family" and his parents were in court supporting him.
"So I am going to extend the maximum leniency that I can, and that is to give you (no) conviction and the good behaviour bond," she said.
As well as the $500 fine and two-year good behaviour bond, Ms Kossiavelos banned Duke from social media for two years and told him he should undertake a deradicalisation program if it was deemed appropriate.
