The couple, who has been dating since September, recently became engaged.
Brand, 34, reportedly popped the question to the 24-year-old "I Kissed a Girl" singer five days ago while the couple was vacationing in Jaipur, India.
Rumors of an engagement began to swirl last month after the British comedian was spotted ring shopping in Cartier's West London store.
Brand eventually purchased a large, square-cut diamond set in a platinum band, which he presumably presented to his bride-to-be.
The couple's exotic trip was also said to be a gift from Brand to Perry for Christmas.
"She told him how much she loved Indian culture while they were eating curry in England, so he surprised her," an insider told reporters.
What may be even more surprising is Brand's transformation from a notorious playboy to a devoted boyfriend.
Brand has been so serious about the relationship that in late November he took a trip to Austria to meet Perry's parents, who are born-again Christians, and apparently convinced them that he's a suitable spouse for their child.
The comedian recently told reporters, "I'd love to marry Katy - hopefully it's heading that way and I'm really happy."
New York Daily News has contributed to the report.