More than 20,000 racers in Sunday’s Great Manchester Run applauded the 22 victims ahead of the starting pistol, while church bells were set to toll at 10:31pm – the time a bomb was detonated at the Ariana Grande concert on May 22, 2017.
The day will be the first time in three years that people in Manchester can mark the anniversary free of coronavirus restrictions.
Those running included friends and family of Barra teenager Eilidh MacLeod who was killed – aged only 14 – in the terror attack.
A post by the Eilidh MacLeod Memorial Trust said a dedicated team were running “in memory of our beautiful angel Eilidh MacLeod”.
The group called on people to donate to support Ms MacLeod’s love of music, posting: "Eilidhs Trust wants to continue this love of music by advancing the musical education of children and young people, primarily but not exclusively in rural Scotland by facilitating access to various music based activities including advanced learning and performance opportunities,” the group said.
"It aims to offer budding musicians the chance to explore their talents, having sourced high quality and affordable music making provisions within their local communities.”
Freya Lewis, 19, who learned to walk again after suffering multiple injuries, fractures and burns at the bombing, raced for the Royal Manchester Children’s Hospital Charity who saved her life.
Ms Lewis, who used a wheelchair for three months and whose best friend Nell Jones, then 14, was killed in the attack, has raised more than £67,000 with her family since the attack.
Cheshire-raised Ms Lewis told BBC Breakfast on Sunday morning that Manchester “means the world to me”, adding: “It’s the most incredible city, I’ll always remember the way it came together and took me in as a Mancunian, as one of their own.”
Also raising money for hospitals in the city, Greater Manchester Mayor Andy Burnham, ran with a team of NHS staff.
Model Ferne McCann was among the runners, along with Coronation Street actors Adam Blease, who plays Dirk, and Sally-Anne Matthews, who stars as Jenny Bradley, for the Dogs Trust charity.
Remembrance services took place at the Glade of Light Memorial in the city centre.
The Duke and Duchess of Cambridge officially opened the permanent memorial earlier this month.
Prime Minister Boris Johnson said the courage shown by people in Manchester in the days following the attack had “touched the world”, as he paid tribute to the victims.
He said: “This was an act of terrorism against the freedoms we all hold dear, but as the people of Manchester demonstrated so courageously in the days that followed, hatred will never win.”
Manchester-born Salman Abedi, 22, surrounded by the throng of youngsters leaving the Arena Grande concert, had exploded his shrapnel-packed rucksack bomb, sending thousands of nuts and bolts shredding everything in their path.
Along with the 22 bystanders killed, six of them children, hundreds more were injured.