The girl was left with her mother's boyfriend at a Perth home while the woman went to a gym for about an hour last Thursday, police said yesterday.
The baby spilt liquid on herself and the man put her in the clothes dryer and turned it on, police said.
"The person we allege has done the act has stated that he has put the child into a clothes tumble dryer, closed the door and turned it on for a couple of minutes," Sen-Det Deb Newman said.
"The child had burns to both feet, to one of her hands, burns and bruising to her back, and bruising to her forehead," she said.
"The injuries are horrific. In my years of being a police officer I have not seen or heard of this type of injury before."
The mother came home to find her daughter suffering serious burns, but her boyfriend did not mention the dryer, she said.
Police investigated after the hospital told them the child's injuries were suspicious and highly unusual.
Sen-Det Newman said that the mother was distraught.
She said the toddler should make a full recovery and be released from the burns unit at Perth's Princess Margaret Hospital for Children this week.
Samuel Marc Barnes Siddall, 21, of the Perth suburb of Beldon, appeared in Perth Magistrates' Court yesterday charged with causing bodily harm or danger.
He was conditionally bailed and ordered to appear again next month.