Councillor Les Trumpeter hailed a move to list the famous old ground as an ACV – which the club said would give a "layer of protection" after it was listed as security against a £20million loan.
And he said it sent a "strong message" to Albion's Chinese owners that they must "act in the best interests of the club".
Mr Trumpeter, who represents Charlemont with Grove Vale on Sandwell Council, first raised the possibility of the ground becoming an ACV at a council meeting last July.
The application was submitted in November by Shareholders for Albion (S4A) – an independent association for minority West Bromwich Albion Group shareholders – in November, and granted earlier this month.
Mr Trumpeter said he was delighted that The Hawthorns was now an ACV. He added: "We now have an element of security over the ground, and it sends out a strong message to the owner that the Albion community stick together and while you are custodian of our historic club you must show transparency and act in the best interests of the club."
The ACV has been backed by the club, with chief executive Ron Gourlay recently telling the Express & Star: "We are pleased the ACV has now been granted. We offered our full support to Sandwell Council and Shareholders for Albion throughout the application process, and I would like to thank all parties for their contributions.
"At no point have there been any plans to sell The Hawthorns – it is our home – but an ACV adds a further layer of protection to the site to secure it for future generations of Albion fans, and that is really important."
West Bromwich East MP Nicola Richards said the move was "extremely positive". "This is an important step to protect the stadium from any possible sale and demonstrate its vital importance to our club and community," she added.
Last month it emerged the club's home for more than 120 years was listed as security against WBA Group's £20million loan from MSD Holdings – at the request of controlling shareholder Guochuan Lai – to aid running, operational and improvement costs.