The True and Fair Party will be revealed on Thursday. Her goal is to disrupt the UK's two-party system, as so many countries have.
"The True and Fair Party will push for vital improvements to the practise and apparatus of government," she says.
The political activist earlier stated that Parliament is currently ruled by "incompetence and self-interest".
"This Government must be held accountable."
"Voters deserve better than the current inept and self-serving politics."
On January 13, at 9 a.m., Ms Miller will launch her new party at the Queen Elizabeth II Centre
The new party is named after Ms Miller's 2012 True & Fair Campaign, which aimed to overhaul the investment and pension industries.
The two entities are not intended to be connected save by name and founder.
Ms Miller rose to prominence after the 2016 EU referendum.
She made news after suing the Government over then-Prime Minister Theresa May's effort to invoke Article 50 without the Commons' permission.
She argued that notwithstanding the referendum result, lawmakers had to approve the UK's exit from the EU.
She has always said her legal action was motivated by wanting to see the UK constitution properly implemented, but she has been accused of trying to stop Brexit.
She also sued Boris Johnson for proroguing parliament in 2019.
Parliament for five weeks was unlawfully suspended, the Supreme Court concluded.
Mr Johnson hoped the prorogation would prevent a postponement of the UK's EU exit beyond October 31 2019.
Former Labour leader Jeremy Corbyn is also rumoured to be launching a new enterprise.
The Islington North MP may turn his Peace and Justice Project charity into a new party, The Telegraph reports.
Sir Keir Starmer removed his whip, preventing him from sitting as a Labour MP for nearly a year.