The couple announced the arrival of Daisy Dove through Unicef, which the couple are both goodwill ambassadors for.
“We are floating with love and wonder from the safe and healthy arrival of our daughter,” the couple said in statement, alongside a black and white picture of them holding Daisy’s tiny hand.
“But we know we’re the lucky ones and not everyone can have a birthing experience as peaceful as ours was. Communities around the world are still experiencing a shortage of healthcare workers and every eleven seconds a pregnant woman or newborn dies, mostly from preventable causes.
“Since Covid-19, many more newborn lives are at risk because of a greater lack of access to water, soap, vaccines and medicines that prevent diseases. As parents to a newborn, this breaks our hearts, as we empathise with struggling parents now more than ever.”
The couple said they have set up a donation page to mark Daisy’s birth, with the money going towards new mothers and their children.
The couple added: “By supporting Unicef, you are supporting a safe start to life and reimagining a healthier world for every child. We hope your (heart) can bloom with generosity.”
Katy and Orlando are engaged and have been dating since 2016.
The I Kissed A Girl singer announced she was pregnant in March, revealing the news in the music video for her single, Never Worn White.
Orlando was previously married to Australian model Miranda Kerr, and they have a son, nine-year-old Flynn.
This article originally appeared on HuffPost UK and has been updated.