The 24-year-old, who had been performing at the venue when the terror attack claimed the lives of 22 people on May 22 last year, shared a touching message on social media as the families of victims and survivors prepared to mark the anniversary.
She wrote: “Thinking of you all today and every day. I love you with all of me and am sending you all of the light and warmth I have to offer on this challenging day.”
Hundreds of those injured in the explosion, and the families of those killed, will be attending a remembrance service at Manchester Cathedral on Tuesday.
They will be joined by the Duke of Cambridge and Prime Minister Theresa May, as well as first responders to the scene, civic leaders and other national figures.
Greater Manchester Mayor Andy Burnham said it was a day to “come together”, tweeting: “Today ... we remember each of the 22 people whose lives were taken & we re-commit to supporting their families & all affected.”
The invitation-only service, held between 2pm and 3pm, will incorporate a national silence at 2.30pm, which will also be marked at UK government buildings.
Members of the public will be able to watch proceedings on a big screen in nearby Cathedral Gardens, while the service will also be screened at York Minster, Liverpool Metropolitan Cathedral and Glasgow Cathedral.
William will meet some of the bereaved families privately following the multi-faith service.
Writing in the Manchester Evening News, Mrs May said: “The targeting of the young and innocent as they enjoyed a carefree night out in the Manchester Arena on May 22 2017 was an act of sickening cowardice.
“It was designed to strike at the heart of our values and our way of life in one of our most vibrant cities, with the aim of breaking our resolve and dividing us. It failed.
“For such appalling acts of wickedness will do nothing but strengthen our resolve to defeat such twisted ideologies and beliefs.
“The resilience and determination shown by this city in the 12 months since is testament to that.”
Later on Tuesday, more than 3,000 singers from local choirs will join forces and share the spirit of solidarity at the Manchester Together - With One Voice event in the city’s Albert Square from 7.30pm-9pm.
Among those performing are the Manchester Survivors Choir, a group made up of people who were at the arena on the night of the fateful concert, and Parrs Wood High School’s Harmony Group, whose post-attack tribute went viral last year.
A mass 30-minute communal singalong finale promises to be the highlight of the concert, with songs including Grande’s One Last Time, One Day Like This by Elbow, Don’t Look Back In Anger by Oasis and Never Forget by Take That.
At 10.31pm, bells will ring out from the city’s Town Hall, St Ann’s Church and St Mary’s RC Church to mark the moment when the attack took place 12 months ago.
Salman Abedi, 22, detonated his device at the end of the concert with 353 people, including 175 children, around him in the foyer of the venue.
A total of 22 people were killed and more than 800 others were either physically or psychologically injured.