One Love Manchester: 'We don't want any fear tonight'
Grande, 23, joined a long list of major musical talents to sing in front of more than 50,000 fans, raising more than £2 million ($2.6 million).
Other artists who performed, in a set which was broadcast live via the BBC, Facebook Live and Twitter, included Pharrell Williams, Katy Perry, Justin Bieber, Little Mix, Coldplay, and the Black Eyed Peas.
Security was tight at the event, with an increased turnout by the police, including many armed officers.
Touching scenes were witnessed moments before the concert, as some of the victims of the May 22 bomb blast outside the Manchester Arena were applauded and cheered as they arrived at the event.
Some 14,000 of the attendees at last month's Ariana Grande concert were given free tickets to Sunday's event and urged to attend despite their obvious fears of another security incident.
Pharrell Williams told his fans he didn't "want to feel or hear or see any fear in this building," before launching into his international hit single, "Happy".
|Security was tight as organisers wanted attendees to feel safe following last week’s incident [Getty]|
Justin Bieber took a moment at the end of his set to "honour the people that were lost".
"We love you so much. To the families, we love you so much," he said.
A viral video from the event showed one police officer dancing with little girls in a circle, inspiring an outpour of emotion on social media.
Grande closed the concert with a touching finale set, including her 2014 hit single "One Last Time", before breaking into tears during a rendition of "Somewhere over the Rainbow".