The pair shared the same close-up image of their faces, with Perry's hand and pink engagement ring clearly visible, from their separate Instagram accounts.
Bloom, 42, captioned it "lifetimes", while Perry, 34, wrote "full bloom".
The pair have been dating since January 2016, but broke up between February 2018 and April 2018. They're both been married before - Bloom to model Miranda Kerr, Perry to comedian Russell Brand.
Perry's ring is rumoured to cost around US$5 million (NZ$7.2 million) due to the quality and number of diamonds involved.
"What looks to be a four-carat fancy vivid pink oval shaped diamond arranged with eight white diamonds around it to assemble a flower 'in bloom' - this ring is truly one-of-a-kind and wildly valuable," Andrew Brown of WP Diamonds told ENews.