Wendy Rowland, 46, who ran a mobile pizza van, had told police she didn't know anything about the KKK and she wanted to protect the name of the centuries-old Black Boy inn at Caernarfon, north Wales.
'She denied being a racist,' said prosecutor Carl Kelvin at Llandudno court, north Wales.
But Rowland, of Heron Way, Nantwich, Cheshire, pleaded guilty to publishing written material which was threatening, abusive or insulting intending to stir up racial hatred or whereby racial hatred was likely to be stirred up on June 13 at Caernarfon.
District judge Gwyn Jones imposed a six months suspended jail term and she must pay £278 costs. She had no previous convictions.
Wendy Rowland, 46, who ran a mobile pizza van, had told police she didn't know anything about the KKK and she wanted to protect the name of the centuries-old Black Boy inn
The prosecution said there had been a series of late-night posts made by Rowland which caused an outcry.
One said : 'Come on Cheshire can you help me....tractors.. let's smash this nonsense.'
Another stated : 'Come on Wales....don't let this happen....we live in a beautiful place why change the Back(sic) Boy...it's history.' Rowland added : 'Let's dress as Ku Klux Klan.'
At first Rowland had claimed her Facebook account had been hacked. She made a public apology in a local newspaper. But she told police she had received many hate messages.
The tractors would have been for a barricade to protect the pub, the court heard.
The posts had been referred to the Attorney General and permission given to prosecute her.
But Rowland, of Heron Way, Nantwich, Cheshire, pleaded guilty to publishing written material which was threatening, abusive or insulting intending to stir up racial hatred
Wendy Rowland, who runs the Amore Pizza mobile pizza van, posted messages on Facebook encouraging people to dress as the KKK ahead of a Black Lives Matter protest in Caernarfon
Defence solicitor Tudur Owen said Rowland had 'completely misunderstood' what the BLM march was about. She thought it had been about the name of the historic pub and the 'obnoxious' remarks were made in drink.
'She may not have understood exactly what she had put on social media.
The judge declared : 'You are very fortunate nothing arose which occurred in the following few days save for you understanding those comments are totally unacceptable in modern society where we should be able to live with each other in peace. Your actions were reckless as to whether hatred would be stirred up.'
He added: 'The potential for harm is great.'