She had been due to perform at the O2 in London yesterday and today but announced last night that she would be suspending her tour until June 5.
A statement from tour promoters read: "Due to the tragic events in Manchester, the Dangerous Woman tour with Ariana Grande has been suspended until we can further assess the situation and pay our proper respects to those lost."
"We ask at this time that we all continue to support the city of Manchester and all those families affected by this cowardice and senseless violence. Our way of life has once again been threatened but we will overcome this together. Thank you."
It means dates in Poland, Germany and Belgium will all be cancelled.
Ariana has received overwhelming support from the media and fellow celebrities in the wake of the atrocity. But a handful of vile trolls have criticised the suspension.
One Twitter user wrote: "If Ariana Grande cancels her tour, the terrorists win."
Another tweeted: "Too bad @ArianaGrande is a spoiled brat. Would love to see her visiting fans at hospital; could be the 1st pop icon to truly condemn terror."
A third wrote: "What I'm gonna say is maybe selfish but I say it. Ariana, if u cancel your tour or ending your career, you let terrorists win."
Some took a more sympathetic approach but still criticised her decision. One posted: "I understand why...but I think the fallen fans would want you to carry on. Dedicate the tour to them, and don't let terror win."
While another added: "Ariana, don't let the terrorists win, get back on tour!"
Other artists have also cancelled and postponed performances as a sign of respect.
Take That cancelled their show in Liverpool on Tuesday and postponed their Manchester gigs on Thursday, Friday and Saturday.
Blondie also cancelled a concert on Tuesday as a "mark of respect".
