It means the former prince will now be known as Andrew Mountbatten Windsor.
A notice has also been served for Andrew to surrender his lease at the Royal Lodge.
The decision from the King follows continued criticism about Andrew's former friendship with paedophile financier Jeffrey Epstein, which was recently intensified by a string of damaging leaks.
Virginia Giuffre, who died in April, accused Andrew of sexually assaulting her after being introduced by Epstein. Andrew has always vehemently denied her accusations.
Andrew latest: King's brother to lose 'prince' title and move out of Royal Lodge
What has Buckingham Palace said?
In a statement on Thursday evening, Buckingham Palace announced the King had started the formal process "to remove the Style, Titles and Honours of Prince Andrew".
"His lease on Royal Lodge has, to date, provided him with legal protection to continue in residence. Formal notice has now been served to surrender the lease and he will move to alternative private accommodation," the statement added.
"These censures are deemed necessary, notwithstanding the fact that he continues to deny the allegations against him.
"Their Majesties wish to make clear that their thoughts and utmost sympathies have been, and will remain with, the victims and survivors of any and all forms of abuse."
Why is this happening now?
The move from the King follows fresh allegations against Andrew, after he announced he would no longer use his royal titles.
Among them was an allegation he sought to dig up information on Ms Giuffre through a Met bodyguard.
It also emerged he had been paying a "peppercorn rent" on his property - piling pressure on him staying at Royal Lodge.
Andrew has not released a statement following Thursday's announcement, but it is understood he has not objected to it.
What has Virginia Giuffre's family said?
The family of Andrew's accuser, who say she died by suicide, said Ms Giuffre "brought down a British prince".
"Today, an ordinary American girl from an ordinary American family brought down a British prince with her truth and extraordinary courage," they said in a statement.
"Virginia Roberts Giuffre, our sister, a child when she was sexually assaulted by Andrew, never stopped fighting for accountability for what had happened to her and countless other survivors like her.
"Today, she declares a victory. We, her family, along with her survivor sisters, continue Virginia's battle and will not rest until the same accountability applies to all of her abusers and abetters, connected to Jeffrey Epstein and Ghislaine Maxwell."
Andrew settled a case with Ms Giuffre in 2022 outside of court for a sum reported to have been around £12m. Andrew has always denied the allegations against him.
In an interview with Sky News, Ms Giuffre's brother, Sky Roberts, said: "[Virginia] should be sitting on this camera with you right now celebrating this but also demanding more justice.
"I think it's a mixed bag of emotions over the last 24 hours but we are just hell bent to not let her voice die."
What have other royal family members said?
It is understood the King's decision has been welcomed by the wider family, including Prince William.
It also appears the UK government was consulted in the process and has deemed the move constitutionally proper and appropriate.
What will happen to Sarah, Eugenie and Beatrice?
Princess Eugenie and Princess Beatrice will retain their titles because they are the daughters of the son of a sovereign.
Andrew's ex-wife, Sarah Ferguson, who had lost her Duchess of York title after Andrew gave up his earlier this month, will make her own living arrangements as well, it is understood.
Together they shared his 30-room Windsor home.
Read More:
Why King could no longer ignore public opinion
King Charles heckled over Andrew and Jeffrey Epstein
The Sandringham homes Andrew could move into
Where will Andrew go next?
The former prince will move, as soon as practicable, to an undisclosed property on the King's Sandringham estate.
There have been reports that Prince William wanted the matter resolved quickly and his uncle out of Royal Lodge by Bonfire night - 5 November - as the prince is due to move his young family to their forever home at Forest Lodge, near Andrew's home, in the coming days.
However, it is understood that Andrew will not relocate until after Christmas, due to the lengthy process of giving up his Windsor mansion.
Sandringham House has been the private home of five generations of British monarchs for more than 150 years and its vast estate includes 16,000 acres of farmland, 3,500 acres of woodland and 150 properties.
It is where the King usually spends Christmas - and the delay in Andrew's move will mean any encounters over the festive period are avoided.
Who will fund Andrew's next accommodation?
That will be privately funded by the King, who will support Andrew with private financial provisions.
How will the titles be removed?
Lord Chancellor, David Lammy, will play a role in the removal of Andrew's titles.
Because of his role, he is responsible for maintaining the peerage roll.
Mr Lammy, who is also Justice Secretary, is being sent royal warrants by the King to strike the Duke from the roll along with his Prince title and HRH style.
Could Andrew still become king?
Charles's dramatic decision effectively ends Andrew's public life and leaves him with the status of a commoner - but he remains eighth in line to the throne.
As of Friday afternoon, Andrew was still listed on the Royal Family's website as eighth in line to the throne - by his now out-of-date title "Duke of York" - just behind Prince Harry's children, Prince Archie and Princess Lilibet.
Sky's royal commentator Alastair Bruce has said that while "in terms of the order of succession nothing changes," there's one thing that would likely stop Andrew from ever becoming monarch.
"I think we should never forget that parliament is sovereign," he said. "And the order of succession exists to delineate who would come next, but it's up to parliament to decide whether it wants that person.
"So I think whether he stays on the order of succession or not, it's highly unlikely, in fact it would never happen, that he would be allowed to succeed."
Every time she has to give her address, it leads to a snide remark or joke at her expense.
She's lived on Prince Andrew Drive in Telford, Shropshire, for 35 years.
As the national scandal around Andrew Mountbatten Windsor - as he is now called - has deepened, it has become increasingly embarrassing for her.
Andrew latest: Virginia Giuffre's brother calls for investigation
A few years ago, another resident started a petition to change the name of the road, and somebody covered up part of the street sign.
"I think we should change it," Shirley told us, "but don't ask me what to."
After a few minutes weighing up the options, she settled on Prince George Drive.
"At least that looks to the future," she added.
Linda Boden has lived on the road even longer - she and husband Phil moved here after getting married 45 years ago.
"We have actually had the conversation this morning, that the name of this road will get changed," Linda said.
Phil told us he wasn't bothered about the name. "It's just a name, it's not the man… I can't tell you what I think [about him] without swearing you know."
Cheryl, who lives nearby, told us what really mattered to her were the victims of the Jeffrey Epstein scandal - particularly the late Virginia Giuffre.
"That poor girl needs justice," she said. "It is ridiculous it has gone on this long to be perfectly honest. That poor family are still living with it."
Read More:
Andrew loses his titles - everything we know
The Sandringham homes he could move into
Julie Harper lives on the adjacent road, called Queen Elizabeth Way, and is more than happy with her road name.
She told Sky News that the King had made the "best decision ever" by removing his brother's titles.
I asked where her sympathies lay within this long-running royal scandal and Julie was unequivocal.
"With anybody who has been sexually exploited," she said bluntly.
Julie believes Princess Anne Drive would be a better name for her neighbours' road.
"She's one of the better ones," she added.
Changing the road name would be a logistical headache for local authorities and residents, with some telling us it did not bother them and they would not fancy the extra paperwork to amend things such as household bills and driving licences.
But Postman Gary told us every time he's making deliveries on Prince Andrew Drive, he feels for the residents.
"We have a little giggle because we know they don't want it named that anymore and I wouldn't either if I lived here. It's probably time it changed."
We did not find anyone on Prince Andrew Drive who disagreed with the King's decision to remove his titles and oust him from his home in Windsor.
The monarchy needs to retain the support of the public across the UK - that's one of the reasons the King has taken such decisive action at this point in the scandal.
Michael Webber, who was a 39-year-old Battery Sergeant Major at the time, previously pleaded guilty to one count of sexual assault. He was sentenced at Bulford Court Martial Centre in Salisbury on Friday.
He had assaulted 19-year-old Royal Artillery Gunner Jaysley Beck, from Cumbria, at a work social event in July 2021.
Gunner Beck, who had joined the Army at 16, said that Webber had "made a pass" at her, put his hand between her legs and "pinned her down" while trying to kiss her.
She pushed him away and spent the night locked in her car before making a complaint to her superiors in the morning.
Webber was given a minor sanction, involving him being interviewed and writing Gunner Beck a letter of apology, but the incident was not reported to police.
An inquest into her death heard she was later bombarded with messages by bombardier Ryan Mason, another senior colleague, who has since left the army, who expressed his love for her.
The 19-year-old's body was found in her room at Larkhill barracks, Wiltshire, on 15 December, 2021. An inquest ruled that her death was a suicide.
During the inquest, coroner Nicholas Rheinberg ruled that "on the balance of probabilities" the Army's failure to take appropriate action "more than minimally" contributed to her death.
An army report published in October 2023 also described Gunner Beck being exposed to "an intense period of unwelcome behaviour", and said it was "almost certain this was a causal factor" in her death.
Wiltshire Police investigated a complaint of harassment submitted by Gunner Beck's family after her death, relating to Mr Mason's behaviour, but found the evidence did not support a criminal harassment case.
Gunner Beck's mother Leighann McCready said outside the court after Webber's sentencing: "No sentence will ever be enough.
"While he serves his time, it's us who will live with a life sentence for what he did. And now the army failed to protect her afterwards."
Ms McCready said her daughter "did everything right, but was failed by the system that was meant to support and protect her".
"She followed the rules, but those responsible didn't follow as they failed to act. Failed to report and failed to follow up," she added.
Ms McCready said she will continue fighting for "real change" in the British Army after Gunner Beck's death: "Not hollow promises or recycled words that have already failed our daughter and continue to fail others.
"Real action means giving soldiers somewhere truly independent to report serious complaints without fear or favour.
"We cannot bring our daughter back. But I will keep fighting to make sure her life leads to change."
Read more:
Army's handling of complaint 'played part in death'
Jaysley Beck's mother urges Army to root out abusers
Sexual harassment probes to be removed from chain of command
Minister for veterans and people Louise Sandher-Jones said the sentencing of Webber was an "important step on the journey to justice".
She said: "We are honouring Jaysley's legacy by bringing about crucial reform, to provide a place where people are proud to work and have faith in the service justice system.
"The Army has accepted the failings identified by the service inquiry in full and has also responded to the recommendations to improve service life across its culture, policies and practices."
Major General Jon Swift, assistant chief of the general staff, said: "We will always be profoundly sorry for the failings that were identified at Jaysley's inquest in February."
He said the Army acknowledges that Webber's sentencing "has come too late for their beloved daughter", adding: "We are sorry we didn't listen to Jaysley when she first reported her assault. We are determined to make sure the same mistakes don't happen again."
Anyone feeling emotionally distressed or suicidal can call Samaritans for help on 116 123 or email jo@samaritans.org in the UK. In the US, call the Samaritans branch in your area or 1 (800) 273-TALK.
Shaine March, 47, of Surrey Quays, London, attacked Alana Odysseos, 32, when she was in the early stages of pregnancy with her third child on 22 July last year.
Today, March appeared in court by video link, from Belmarsh prison, after initially refusing to come to the Old Bailey.
He did not react as Ms Odysseos's family spoke of the devastation he had caused them.
'It's only sentencing'
Defence barrister, Sandip Patel KC, said March had refused to leave his cell and had told prison staff: "It's only sentencing."
March, who previously admitted to manslaughter by diminished responsibility but denied murder, changed his plea and admitted to the murder of Ms Odysseos on the seventh day of his trial.
Following the guilty plea, Mr Justice Murray discharged the jury and lifted reporting restrictions of March's previous conviction for murder.
It could then be reported that March was aged 21 when he killed a man by stabbing him in the neck at a McDonald's restaurant in January 2000.
He was convicted of the murder of Andre Drummond, 17, in July that year and jailed before being released on licence in early 2013.
He was then recalled to jail later that year after an assault on another partner in July, and released again in February 2018.
Before the killing, March had been seeing Ms Odysseos for around four months.
The court heard they had an argument hours before over whether to abort their unborn child, with Ms Odysseos heard to have said: "I don't want to kill my baby."
Members of the public in Lynnmouth Road rang 999 after finding Ms Odysseos outside her home wearing a nightie and a dressing gown, clutching her right side.
She was bleeding from multiple stab wounds and shouted: "Shaine stabbed me, he stabbed me. Help, help."
March walked away and the victim died on the ground outside her home, having suffered stab wounds to her chest, stomach, pelvis, shoulders, buttocks, right arm, thighs and lower legs.
Before throwing his mobile phone in a drain, March recorded a voice note saying: "Mum, I just killed a woman, and I'm going back to jail."
After his arrest, March told police: "I did it. I killed her Alana Odysseos. I killed her hahahaha."
'I want him to die in prison'
The victim's mother, Karen Cronin, said: "Alana, my beautiful kind and loving daughter, left this earth in the most callous and brutal way imaginable.
"The person who has done this to my daughter - who I don't think deserves the respect of using his name - is evil and a coward. Why did he have to resort to the level of violence he used?
"The anger I feel towards him doesn't feel Christian so I can no longer go to Church. I will never have forgiveness in my heart.
"I want him to die in prison. He should never be let out."
'We will never get over our loss'
Father, Alan Yates, said his daughter changed after meeting March and became a "timid vulnerable person who was not our Alana".
He said: "I hope a sentence is given that means Shaine March will never cause another family the pain and loss we are suffering. It is unimaginable and we will never get over our loss.
"Every day I wonder why he didn't walk away. Alana was pregnant with his child. This meant nothing to him."
It said the expansion of European competition was behind the move to reduce what is traditionally a packed schedule.
The fixture will be Manchester United's home game against Newcastle United at 8pm.
The Premier League said in a statement: "The Premier League would like to acknowledge the circumstances that have led to a reduced number of matches on Boxing Day this season, impacting an important tradition in English football.
"There are now several challenges to Premier League fixture scheduling rooted in the expansion of European club competitions - which led to a revision of our domestic calendar ahead of last season, including changes to the FA Cup.
"This ultimately left the Premier League as a 33-weekend competition - fewer than previous seasons, despite being a 380-match competition since 1995."
Read more:
World Athletics blames employees for stolen £1.3m
Sheffield Wednesday fans 'elated' after administration
It added that this year's Boxing Day falling on a Friday had also impacted the fixture list.
The remaining fixtures will be spread over the weekend, with seven on Saturday and two on Sunday.
'Special arrangements have been made'
The statement added: "With fewer weekends to work with, the League is bound by how the calendar falls.
"The League can give an assurance that next season there will be more Premier League matches on Boxing Day - as the date falls on a Saturday.
"As with previous years - and in keeping with our commitment to clubs - special arrangements have been made to allow more time between games played across the festive period.
"This will allow greater time for players to recover, with the rest periods between rounds 18, 19 and 20 being increased to ensure that no club plays within 60 hours of another match."
'Thoughtless and ridiculous'
The Football Supporters' Association criticised the move in a strongly-worded statement on X.
It read: "The Premier League's TV selections for Xmas and NY have finally been announced a fortnight after they were supposed to be.
"Newcastle United's game at Old Trafford - the longest trip of that game week - has been selected for a ridiculous 8pm kick-off on Boxing Day. Thoughtless."