The US star urged her Twitter followers to watch the video for Ware's single 'Wildest Moments' and predicted that the singer will become an international success.
"I think this lil' lady is going to be massive," Perry tweeted, with a link to Ware's 'Wildest Moments'. "So if you haven't discovered her yet, jump on board."
Ware recently signed a US record deal with Cherrytree Records and will release her debut EP 100% in December.
"I'm extremely excited to be joining Cherrytree," said Ware previously said of the deal.
"Not only am I a huge fan of the artists already on their roster, but I have seen how they have nurtured and helped other UK artists."
Jessie Ware's debut album Devotion reached number five on the UK chart earlier this year.
Watch the music video for Jessie Ware's 'Widest Moments' below: