Huge crowds will be hoping to get a glimpse of the Queen and other royals - including Harry and Meghan, who are jetting in from California with their children - as a series of big events are held in London across the four days.
Meanwhile tens of thousands of street parties are set to be thrown up and down the land to mark the monarch’s 70-year reign.
The commemorations kick-start with the traditional Trooping the Colour military spectacle on Thursday, involving more than 1,500 officers and soldiers and 350 horses from the Household Division.
The Queen’s attendance is only likely to be confirmed on the morning, with royal fans hoping to see her appear on the balcony with her family for a special flypast, and possibly even review the troops.
In the evening, more than 3,000 beacons will be set ablaze across the UK and the Commonwealth in tribute to the Queen, with the principal Tree of Trees beacon illuminated outside the Palace.
A service of thanksgiving at St Paul’s Cathedral will be held on on Friday, while on Saturday the BBC’s Party at the Palace will entertain a live crowd of 22,000 people and a television audience of millions.
On Sunday, millions will gather for patriotic street parties, picnics and barbecues, with more than 85,000 Big Jubilee Lunches being held across the UK.
The finale is the Jubilee Pageant through the streets of London, with a cast of 6,000 performers and close to 200 celebrities joining the carnival procession.
19:12 , Lily Waddell
Thank you for following our coverage today.
Revealed: The world records Queen Elizabeth holds
18:27 , Josh Salisbury
Although many people are familiar with the Queen’s status as longest-reigning living monarch, she also holds a raft of other records, including appearing on the most number of currencies.
Ahead of the Queen’s Platinum Jubilee, marking her 75-year reign, Guinness World Records has revealed the raft of records she currently holds.
“Most countries to be Head of State of simultaneously" is a record which she set in November 2021, at 15 different countries.
She became the longest-reigning living monarch in October 2016 after the death of King Bhumibol Adulyadej of Thailand.
She also holds the Guinness World Record for the most portrayed living monarch, for appearing on the most currencies - at least 33 - and she is also the wealthiest Queen, with an estimated wealth of £370 million.
Other royal-related records include the monarch’s St Edward’s crown being the world’s most valuable.
Harry and Meghan to join royals at Trooping the Colour
18:03 , Josh Salisbury
The Duke and Duchess of Sussex will join the royal family at Trooping the Colour as the Prince of Wales deputises for the Queen - who will not take part in the ceremony, Buckingham Palace has confirmed.
Harry and Meghan will have a prime vantage point with members of the monarchy as they watch Charles inspect the guardsmen and officers and take their salute on Thursday.
The pair are not working royals after stepping down in 2020.
After the ceremony, the Queen will join working royals on the balcony to watch the traditional fly-past of aircraft.
Prince Andrew, who left public duties after his US civil sex case, which he settled out of court, is not expected to join the royals.
The Sussexes had been expected to join the congregation for Friday's service of thanksgiving for the Queen's 70-year reign at St Paul's Cathedral, but their participation with Trooping is an added element.
Queen’s Jubilee will show London ‘at our best’, vows senior Met officer
17:26 , Josh Salisbury
The Queen's Platinum Jubilee will show the Met Police at their best, a senior officer has vowed.
Deputy Assistant Commissioner Barbara Gray has spent months organising the force's operations over the Jubilee weekend.
She told the PA news agency on Wednesday: “Policing the Jubilee is an absolute privilege and that privilege is whether we are policing here at Buckingham Palace and in the Mall or whether we are working across every community in London.
“And that is what people will see.
“They will see police officers across London throughout this weekend and I think that this is just such a fabulous opportunity to show London at its best and to show the Met at its best.
“And really to take so many opportunities to speak to members of the public and do what it is we do on a daily basis, out there keeping people safe, and that's what we are aiming to do for this weekend.”
Queen will light principal Jubilee beacon - Buckingham Palace
17:21 , Josh Salisbury
The Queen will lead the lighting of the principal Jubilee beacon in a special ceremony at Windsor Castle on Thursday evening, Buckingham Palace has announced.
The new engagement, added to the Queen's jubilee diary, will see the monarch symbolically touch the Commonwealth Globe of Nations, created for the Beacons projects, in the castle Quadrangle.
This is the signal for the start of the illumination of the Tree of Trees principal beacon at Buckingham Palace.
Waiting at the palace will be the Duke of Cambridge, representing his grandmother, as part of a special dual ceremony.
Sturgeon: All of us should pay tribute to Queen for Jubilee
16:56 , Josh Salisbury
First Minister Nicola Sturgeon has congratulated the Queen on a “lifetime of service” ahead of her Platinum Jubilee.
Ms Sturgeon led a parliamentary tribute to Queen Elizabeth II, who is due to celebrate 70 years of reign from tomorrow.
Speaking in the Scottish Parliament, the First Minister said the Queen had played an “integral role” in the story of modern Scotland and said it was no surprise the occasion was to be celebrated so widely.
And she urged all Scots to mark Her Majesty’s “values of integrity, wisdom, justice and compassion” - regardless of their views on the institution of the British monarchy.
She said: “It is of course the case that there are, and always have been different views in our country, indeed in this chamber, about the institution of the monarchy, and the democratic right to express those views is always to be celebrated.
“But this occasion of the Platinum Jubilee is not just about an institution. It is above all about the life and service of an extraordinary woman, someone who had no more choice than any of us do about the circumstances into which she was born- but someone who has given a lifetime of dedicated service.
“We should all pay tribute to that”.
The Mall very busy ahead of celebrations
16:09 , Josh Salisbury
Pictures show that The Mall is busy this afternoon, as royal fans camp out ahead of tomorrow’s celebrations.
When will supermarkets be open during the Jubilee?
16:03 , Josh Salisbury
Supermarkets’ opening hours may vary during the Jubilee, meaning anyone needing street party essentials will need to check before making the journey.
Aldi, Asda and Tesco are among those generally following their normal hours over the weekend, although some branches differ depending on location.
However, other major supermarkets such as Waitrose say their shops may close earlier than normal or close entirely on Sunday.
Explained: What events will mark the Queen’s Platinum Jubilee?
15:34 , Josh Salisbury
Four days of celebrations will begin with the Queen’s official birthday parade at Buckingham Palace on Thursday.
The Trooping of the Colour parade will ride at 10am from The Mall to Horse Guards Parade, with the Prince of Wales, the Duke of Cambridge and the Princess Royal on horseback.
It will close with a six-minute RAF fly-past by more than 70 aircraft. More than 3,000 Jubilee beacons will be lit across the UK in honour of her Majesty.
On Friday, a traditional service of thanksgiving will be held at St Paul’s Cathedral. Just before 11am, England’s largest church bell Great Paul will ring to mark the service.
On Saturday, the Princess Royal is expected to represent the monarch at the Epsom racecourse, where up to 40 past and present jockeys are due to form a guard of honour for her Majesty.
In the evening, Queen and Adam Lambert will open the BBC’s Party at the Palace, which runs from 8pm to 10.30pm.
On Sunday, an expected 10 million people will join street parties, barbecues and picnics, where they can recreate the official Platinum Pudding, a lemon and Swiss roll amaretti trifle.
The finale will be the Jubilee Pageant running through the streets of London. From Whitehall to Buckingham Palace, the parade will include original film footage from the coronation, a gospel choir joining the Band of Her Majesty’s Royal Marines and huge puppets on the carnival route.
Royal fans pose for photographs on The Mall
15:14 , Josh Salisbury
Explained: How to watch military flyover for Trooping the Colour
14:45 , Josh Salisbury
The annual Trooping the Colour event will take place on Thursday, June 2, as the official start to the Jubilee celebrations featuring 1,500 officers and soldiers.
A military flypast featuring more than 70 aircraft will follow the parade, first assembling around 11.45am in North Seam, Southwold, Suffolk, and Southend area. It will then make its way towards London via Swaffham, Thetford, and Colchester.
It will appear over central London at around 12.40pm. The aircraft is expected to pass over Buckingham Palace at around 1pm, where the Queen will be watching from the palace balcony.
It will then disperse over Kent, Surrey, Berkshire, Buckinghamshire, Oxfordshire, Gloucestershire, and Wiltshire.
More details on how to follow the flyover can be found here.
What will the weather be like for Platinum Jubilee?
14:37 , Josh Salisbury
There should be plenty of sunny spells for street parties planned for the Jubilee, though forecasters warn not to expect a bank holiday scorcher.
Thursday will be dry and mostly sunny for southern areas such as London, when the Queen is expected to make an appearance on the Buckingham Palace balcony to mark the start of the celebrations after Trooping the Colour.
However, northern areas will see spells of showery rain, said the Met Office.
It will be a similar picture for most on Friday - when a service of thanksgiving is planned at St Paul’s Cathedral - though rain could fall in central and northern England, according to the Met Office.
Saturday is forecasted to have light rain in the capital with temperatures hitting 18C.
Sunday could be also be worrying as the Met Office said the weekend is looking “quite settled, with most places seeing quite a bit of fine and dry weather again, with a risk of showers in the South East and east coast”.
Read our full story here.
Monarchy ‘stronger than ever'
14:33 , Josh Salisbury
The monarchy is “stronger than ever” despite recent scandals, the Culture Secretary has said.
Speaking ahead of the Queen’s Platinum Jubilee celebrations, Nadine Dorries told BBC Radio 4’s World At One programme: “Our monarchy is special in the UK, we must not forget that, and I think the future looks great and the Commonwealth is stronger than it has ever been and I believe so is the monarchy.”
She added that Jubilee celebrations provided an opportunity for people to “relax a bit and have some fun” after “a terrible two years with Covid”.
Eugenie: My ‘grannie’ is a constant rock to so many
14:17 , Josh Salisbury
Princess Eugenie has paid a moving personal tribute to her “grannie” the Queen on the eve of the Jubilee.
Eugenie, writing in The Spectator magazine, said she hoped her one-year-old son August would grow to have the Queen’s “patience, her calmness and her kindness while always being able to laugh at himself and keep a twinkle in his eye”.
She described the nation’s longest-reigning monarch as having transcended time and been “a constant rock for so many”.
She wrote: “Seventy years is really quite something, isn't it?
“The Jubilee stands as a testimony to a woman who has transcended time and has been that constant rock for so many when the world can feel so fragile.”
Campers come all over world to catch glimpse of royals
14:12 , Josh Salisbury
Campers have made their way from as far as North Carolina to camp out on the Mall ahead of the Jubilee.
Melanie Deal, 59, from North Carolina, said she was interested in the royal family for the “celebrity” and because the Queen provides “a constant for you all”.
Mary-Jane Willows, 68, a retired charity executive from Cornwall, said she first camped out for the Diamond Jubilee in 2012.
“She has given 70 years of her life to serve us, the country,” she said. “That’s what she said at her coronation and she’s done it every second of every day.
With Mary was her friend Donna Werner, 70, from Connecticut. Donna first developed an interest in the royal family after taking a bicycle tour through Britain in her youth.
“I just fell in love with the country,” she said.
Her first royal event was the wedding of the Duke and Duchess of York in 1986, where she slept on the streets for two nights, while pregnant.
Donna added that she would love to see the United States re-join the Commonwealth, adding: “We should never have had that tea party”.
Excitement builds as nation prepares to mark Platinum Jubilee
14:01 , Josh Salisbury
Excitement is building as the nation gears up to celebrate her Majesty’s historic Platinum Jubilee.
Huge crowds are expected on the steets of the capital over the extended bank holiday weekend amid a series of big events to mark the occasion.
The commemorations officially kick-start with the traditional Trooping the Colour military spectacle on Thursday, but enthusiasts are already camping out on the Mall ahead of the wekeend.
We will be bringing you all the latest developments throughout the day ahead of the historic milestone.