The Oscar-winning picture made $1.27bn (Â£857m) at box offices worldwide, and led to record sales of related merchandise.
Frozen 2 will reunite the team behind the original feature, including director Chris Buck, writer Jennifer Lee and producer Peter Del Vecho.
The studio did not name a release date.
Shares in parent company Walt Disney were up by almost 4% following the news.
Toy-maker Mattel, which currently owns the license to sell Frozen products, saw its shares rise by almost 5%.
Last month, Disney credited the continuing success of toys based on Frozen for an "incredibly strong quarter".
Net income rose 19% to $2.2bn (Â£1.5bn) in the three-month period, with revenues up 9% to $13.4bn - both figures better than forecast.
In December, Frozen became iTunes' biggest-selling movie of all time, while the soundtrack sold more than any other album in the US in 2014.
Additionally, DVD and Blu-ray sales of the animation broke the three million mark on the first day of their release.

The body of the man in his 70s, was found at the house in Nettleden Road, Little Gaddesden, near Berkhamsted, on Saturday afternoon.
A man in his 80s was also taken to hospital, a police spokeswoman said.
Detectives want to question 55-year-old Ian John McLoughlin, also known as Ian John Baker, and have warned people not to approach him.
Det Ch Insp Martin Brunning, from the Bedfordshire, Cambridgeshire and Hertfordshire major crime unit, said: "The investigation is still in its early stages.
"However, we are continuing to treat the death as murder. We urgently want to speak to Ian McLoughlin in connection with this offence."
He is described as white, about 6ft (1.8m) tall, with straight, greying, collar-length hair and of average build.
He is believed to have been wearing sunglasses, blue jeans or three-quarter length trousers and a dark blue, light blue and white checked short-sleeved shirt with a button-down collar.
Anyone with information has been urged to contact police or Crimestoppers.
Officers have been conducting additional patrols in the area to provide reassurance to residents.

Swiss Xhaka, 24, is believed to have been with a friend who had visited him in London and was returning home.
The man is understood to have arrived late for his flight back to Germany and was not allowed to board.
It is at this point that the racial abuse is alleged to have occurred.
Arsenal have declined to comment other than to say it is a private matter that is now in the hands of the police.
A spokesman for the Metropolitan Police told the BBC: "Police were called at 19:29 GMT on Monday, 23 January following an allegation that a member of staff had been racially abused at Heathrow Airport, Terminal Five.
"The allegation was made by a third party. Officers attended and spoke with a man in his 20s. He was not arrested. He voluntarily attended a west London police station where he was interviewed under caution. Enquires continue."
The incident occurred just over 24 hours after Xhaka was sent off during his team's 2-1 victory over Burnley in the Premier League.
Disney has announced it will produce a sequel to its runaway hit Frozen, which last year became the highest-grossing animated film of all time.
[NEXT_CONCEPT]
Police are seeking a man over the murder of an elderly man found dead at a house in Hertfordshire.
[NEXT_CONCEPT]
Arsenal midfielder Granit Xhaka has been interviewed under caution by police following an allegation he racially abused an airline staff member at Heathrow on Monday night.