The pop superstar, 39, had been fighting to end the complex legal arrangement she was placed under in 2008 amid substance abuse and mental health issues.
The conservatorship had long outraged the singer’s millions of fans, but pressure to terminate it had ratcheted up over the last 12 months as the previously silent Spears brought her grievances into the public eye.
Over the summer she delivered bombshell courtroom testimony alleging the arrangement – which is usually reserved for the very ill or old – was abusive and deprived her of basic human rights such as getting married and having more children.
Spears’s explosive interventions have been key in Friday’s momentous decision.
Brenda J Penny, sitting at Los Angeles Superior Court, listened to 30 minutes of testimony before delivering her decision.
She added two caveats – specifying that an accountant serving as a temporary conservator should retain some powers – but the complex legal arrangement is “effective today… thereby terminated”.
Judge Penny cited California law as she made her decision and there was no dissent among the parties inside the packed courtroom or joining virtually – which included Spears’s parents, father Jamie and mother Lynne.
John Zabel, a certified public accountant, was appointed temporary conservator in September and retains two basic powers.
He is able to transfer assets to the Spears estate and execute “supplemental” decisions on its behalf. Spears’s lawyer Mathew Rosengart, who accepted the arrangement was “a little bit unusual”, said it was for his client’s “financial and personal wellbeing”.
Mr Zabel’s lawyer called his abilities “very limited administrative powers”.
Lawyers for Jodie Montgomery, the conservator of Spears’s personal affairs, have filed a termination plan under seal to help with her transition to full independence.
Lauriann Wright, Ms Montgomery’s lawyer, told the court there is no reason Spears cannot live a “safe, happy and fulfilling life”.
Mr Rosengart, who was applauded by fans of the singer as he entered the courtroom, ended the hearing by thanking the judge for allowing him to join the case in July.
News of the termination was met with wild celebrations by the dedicated #FreeBritney supporters who made their regular pilgrimage to gather outside court for the hearing.
The decision to end the arrangement closed one of the most controversial chapters in modern pop music history and handed Spears the keys to her estimated 60 million dollar (£45 million) estate.
Spears was also granted her wish to be freed without the need for a psychiatric evaluation, which she made clear she was against.
The judge’s decision was the culmination of years of public and private legal wrangling from multiple parties who faced allegations they did not have Spears’s best interests at heart.
Jamie had been in control of his daughter’s money but was suspended from that role in September, much to Spears’s delight.
The court heard their relationship had disintegrated and she saw him as a major obstacle between her and a return to living a normal life.
The conservatorship has also led to a breakdown in Spears’s relationship with her family.
Jamie, 69, was crucial in the conservatorship’s formation in 2008, arguing his daughter could no longer look after herself.
She had disintegrated in the public eye and in 2007 infamously shaved her own head. Spears lost custody of her two sons with ex-husband Kevin Federline.
However, as the conservatorship continued year after year, fans began to query how a global pop powerhouse was able to perform to packed-out arenas if she was incapable of looking after herself day-to-day.
Jamie, who was an inconsistent presence in his daughter’s early life and who has struggled with alcohol issues, faced accusations he was financially benefitting from the conservatorship.
His lawyers argued it was his smart management that saved the singer from financial ruin.
A decisive moment in the conservatorship came in July when Judge Penny allowed Spears to hire her own lawyer after more than a decade of having a court-appointed representative.
Mr Rosengart, a high-power Hollywood litigator, took over and quickly made good on his promise to take a more aggressive approach.
He accused Jamie of attempting to extort his daughter and is calling for a forensic financial audit of the conservatorship.
Following Mr Rosengart’s bulldog-like approach to the case, Jamie called for the conservatorship’s immediate termination.
He said his daughter has shown she was able to look after herself.
However, Mr Rosengart has questioned Jamie’s motive’s for wanting the conservatorship to end and accused him of attempting to avoid scrutiny.
Jamie has also denied bugging his daughter’s conversations, an accusation that sparked further outrage from Spears’s supporters.
A new legal fight now looks set to begin.
Jamie replaced his former legal team with Alex Weingarten, a lawyer who specialises in the issues that may be imminent.
And Tri Star Sports and Entertainment Group, the former business managers of Spears, have fought back against Mr Rosengart’s calls for a forensic look into their involvement in the conservatorship.
Now she is free from the arrangement, Spears is able to marry 27-year-old fiance Sam Asghari, the Iranian-born actor and model she met on the set of a music video in 2016.
The next hearing in the case is set for December 8.