The US pop star was photographed on social media hugging youngsters at the Royal Manchester Children’s Hospital ward, with one father left in tears by the visit.
It comes ahead of Grande’s all-star benefit concert on Sunday, less than two weeks after a suicide bombing at her gig in Manchester which killed 22 people and injured dozens more.
Peter Mann, whose daughter Jaden was injured in the attack, posted several photos of Grande and the youngster on Facebook.
— jaden farrell mann (@dustyblu10) June 2, 2017
He wrote: “This means more to us than all the amazing things people have done this week. When your daughter asks after her 2nd operation is Ariana OK?
“So happy she came I could burst! Never seen Jaden so happy! Even cried again myself.”
Grande arrived back in the UK on Friday morning ahead of the One Love Manchester concert on Sunday.
Musicians including Justin Bieber, Katy Perry, Coldplay, Take That and Miley Cyrus will join her for the event which is raising funds for victims and their families.
Unfortunately ticket scalpers started listing tickets online after the concert sold out in just six minutes. eBay has removed listings and Ticketmaster has told fans it will cancel tickets which are being shopped around online.
Grande has also confirmed that her Dangerous Woman tour will recommence on June 7 in Paris before she heads to Australia in September.
The singer’s Australian tour will kick off at Melbourne’s Rod Laver Arena on September 4 and 5 before shows at Sydney’s ICC Theatre on September 8 and 9, and Brisbane’s Entertainment Centre on September 12.
Her hospital visit comes as police investigating the suicide bombing seized a car which they say could be “significant” to the investigation.