The announcement comes just over a month after he left Our Local Community.
Cumberland councillor Steve Christou has joined the Libertarian Party, 6 News has learnt.
Christou, a former Labor member, was re-elected in Cumberland's Granville Ward at the September local government elections in NSW as a member of Our Local Community (OLC). In late October, he announced that he had left OLC.
The defection gives the Libertarians an eleventh local councillor in NSW after ten were elected in September, while there are also two endorsed Libertarians in local councils in Victoria. Trudi Paton, a member of the party running without endorsement, was elected to Cardinia Shire Council as an Independent Libertarian, and Joel Grist was elected to Surf Coast Shire Council as an Independent Libertarian as part of the Back To Basics Team.
At the time he left OLC, Christou said he would form a new political party with Liverpool councillor Peter Ristevski, who had also left OLC. In a statement to 6 News, Ristevski said: "We are still continuing on the registration of the new party".
"We have garnished all the necessary signatures and will be lodging the application shortly, but unfortunately it won't be ready for the next federal election. Steve has ambitions to run and I support him with his decision."
Libertarian MLC John Ruddick says his party plans to contest all 128 LGAs at the next NSW local election in 2028.