Office workers, school children, councillors, pensioners, students and police offcers were among those who attended a vigil in George Square.
Despite being arranged at short notice, and with grey skies overhead threatening to open at moment, around 250 people were present.
Many had brought floral tributes, with foot of the Scott Monument in the centre of the square becoming an impromptu memorial garden.
“It seems that too often we gather in George Square in memory and in condolence when there has been an act of terror in the world and innocent lives taken,” Glasgow City Council leader Susan Aitken said in a short speech.
“This one was very close to home in a city we have a great deal in common with. Many of us will have visited and enjoyed it - just like those young boys and girls, who were attending what will have been their first pop concert. Too many of them will not be going home.”
Gabrielle Brownlie was among those attending the vigil. “It’s awful to see children attend a concert, a night they should have enjoyed, and not make it home,” she said.
The 20-year-old from Glasgow added: “I think it’s important to attend events like this to show we’re united.
Emma Wilson, from Denny, near Falkirk, said: “It’s a terrible tragedy. But by coming together, we’re showing we have no fear.”
Many in George Square were visibly upset as members of the public were invited to lay flowers.
Malcolm Thomson said the young age of some of the victims - with an eight-year-old girl from Lancashire among those killed - made the attack particularly hard to deal with.
“I felt that what happened was so bad - so evil - I felt compelled to show some kind of solidarity with the poor families who have lost children,” he said.