The singer was set to perform on Sunday, her birthday. There was no information as to whether she will reschedule.
"I love my fans in Brussels and at this time I am being advised to cancel my show for the safety of my fans, my band, crew and everyone involved with the tour," she wrote on her social media pages. "I hope to see you soon and send my prayers and eternal love, laughter and light to my Lambs."
On Tuesday, ISIS militants attacked the Belgian capital, leaving 31 dead.
Among the casualties were two Americans and citizens of the Netherlands, Peru, the U.K, China and France. A U.S. official confirmed to ABC News that the two Americans were living in Europe at the time of the attacks. Though it has been confirmed that they were spouses of U.S. personnel, their names have not been released.