During a day of mourning, survivors and bereaved families paid tribute to those who died in the blaze on 14 June 2017.
A silent march took place around the neighbourhood with Jeremy Corbyn in attendance.
The Labour leader said the fire represents “everything that is unequal and wrong about this country”.
Wearing a green fabric sash around his neck as a sign of solidarity, he greeted and hugged residents before writing a message on the tower’s perimeter fence.
It read: “Love and sympathy to all at Grenfell.
“Together we mourn. Together we overcome.”
Prime Minister Theresa May apologised on Wednesday for not meeting survivors of the fire immediately after it happened, saying “I regret that”.
Silences were observed across the country by thousands throughout the day, including MPs, the London Fire Brigade and the Royal Family.
The England team in Russia also observed the silence.
Hundreds attended a private ceremony near the foot of the block in west London.
Many arrived dressed in green, the colour that has come to symbolise the tragedy.
There was a 72-seconds silence which fell over North Kensington shortly before midday, that led a minute’s commemoration observed across the country, including at government buildings, the Palace of Westminster and by the Queen and the Duchess of Sussex in Chester.
The Mayor of London was among those to lay a wreath at the fence still separating the tower’s hollowed skeleton from the rest of London.
Celebrities including Adele and Stormzy also joined in commemorations.
Adele has been a vocal supporter of the families and the fire service.
Stormzy has also been a supporter of the families, as well as being critical of the government’s response.
British singer Marcus Mumford also attended.
Nicholas Burton, a former 19th floor resident whose wife, Maria del Pilar Burton, died in January, was the first of the bereaved to lay flowers.
He paid tribute to his wife, saying he was thinking about her during the silence.
He added: “It was quite weird, I went into the sports centre and I hear ‘Hi Nick’ and it’s Adele calling me over, who introduced me to her new husband and then Marcus comes over and we had a hug, then Stormzy comes over, they have all been unbelievable.
“I was thanking them for all they’ve done behind the scenes that no-one knows about.
“It was just nice and normal, they may travel the world and are known to millions but down on the ground they are normal people with big hearts wanting to give, this is there community as well, they feel part of it.
“That persona of being famous is out of the window and now they are part of the Grenfell community.”
Many held huge green hearts emblazoned with words such as “humanity”, “love”, “unity” and “grace” at the various commemorations that took place throughout the day.
The day’s first service saw a community mosaic unveiled and a gospel choir perform songs including Bridge Over Troubled Water.
The names of all the dead, including stillborn baby Logan Gomes, were read out by different members of the community.
After each finished their turn, they said: “Forever in our hearts.”
Members of the public were able to watch the ceremony from a giant screen put up outside nearby Kensington Aldridge Academy.
NHS support workers were on hand in case any residents became distressed.
Silent marches took place throughout the day, between memorial services taking part in different locations.
One mourner collapsed to the floor as a march along Silchester road to the tower reached the base of the site.
Parallel commemorations took place nearby, including an 11am service of remembrance at St Helen’s Church.
Among those in attendance was Tottenham MP David Lammy, who was friends with victim Khadija Saye.
He said: “I don’t think a year ago we could have envisaged how little support the community would be given by the local authority and the Government, and that’s in their own words.
“That has not been the best of our country.
“We need a redoubling of effort in the year ahead, it needs to be much, much better, we need to get those people housed, and we need to continue to support those in the north Kensington area that are deeply traumatised.”