It's been 518 days since four-year-old Cleo Smith was found alive after being snatched from a campsite in remote Western Australia.

It was a missing persons case that gripped the country and tomorrow the man who kidnapped her and kept her captive for 18 days will learn his fate.

Terence Kelly will be sentenced for abducting the girl from the isolated Blowholes Campground in the early hours of October 16, 2021, as her family slept.

READ MORE: How Cleo Smith was found

That morning her mum Ellie Smith woke to find her daughter gone.

For the next 18 days a desperate search for Cleo unfolded, her devastated parents pleaded for her safe return and thousands followed the case, holding their breath.

On the night of November 3, Western Australian detectives broke into a locked home in Carnarvon and found the four-year-old.

"My name is Cleo" were four words heard around the nation after they were captured on a police body cam.

Her discovery was branded a miracle and the rescue made headlines around the world.

Kelly was arrested in town when officers stopped his car. He was charged the next day and flown under heavy guard to one of Perth's toughest prisons.

Last year the 37-year-old pleaded guilty to one count of forcibly taking a child under 16.

Tomorrow, Kelly will be sentenced.