The comedian, 39, shared a series of Instagram Stories in which she came across the pop star's contribution to the Calm app.
'I'm Harry Styles and tonight, I'm going to help you drift off to sleep,' Harry's voice could be heard saying in a recording playing on Celeste's tablet.
Calm: Celeste Barber (pictured) enjoyed a soothing bed time story on Sunday night, read to her by none other than Harry Styles
'That's... that's nice!' the Australian funnywoman said in a video clip, shocked and impressed.
Harry helps Calm app users to sleep as he lends his voice to a 30 minutes sleep story, and his contribution has been available since last year.
The Watermelon Sugar hitmaker, who initially invested in the company's Series A back in 2018, voices the new Dream With Me story.
Help: The comedian, 39, shared a series of Instagram Stories in which she came across the pop star's contribution to the Calm