Steve Bullcock stood for the Barnsley Independent Group in last month’s elections.
He came second in the Central ward with almost 30 per cent of the vote but he will now join the Yorkshire Party.
He said: “I am delighted to have joined the Yorkshire Party and look forward to working with Party members across Yorkshire in the weeks and months ahead.
“Having met the Yorkshire Party South Yorkshire Mayoral candidate Simon Biltcliffe, I have been incredibly impressed with the party’s ambitions for Barnsley.
“I believe the Yorkshire Party will be the main opposition to Labour at next year’s Barnsley Council elections - I look forward to fighting as a candidate.”