The 96km journey, sponsored by Rotary Club of Karrinyup, will take her 11 days complete, trekking through dense rainforest and rugged terrain.
Ms Davis first became interested in the hike after reading about disabled athlete Kurt Fearnley crawling the famous trail in 2009.
The 22-year-old said she wanted to gain a greater appreciation of what the soldiers faced and relate it to her work as an occupational therapist.
‘I want to relate the hardship that the soldiers faced on the Kokoda trail to that of children with a disability and the daily struggles their families go through,’ she said.
Training almost daily leading up to her departure on Saturday, Ms Davis accepted the physical aspect of the hike would be challenging.
She said she was expecting it to be difficult on other levels too, as she learned more about what happened there more than 70 years ago.
‘To be able to put into place what we’ve read about it, to actually see it and make that emotional connection to it, I’m excited but nervous as well, I’ve been doing a lot of preparation, but I’ve heard that no preparation is ever really enough for when you get there.’
Rotary club director of youth services Robyn Cleaver said the Karrinyup club sponsored two people, aged 18 to 25, to visit an historic Australian military site each year.
She said applicants needed to be community-minded and want to expand their knowledge and understanding of veterans and their sacrifices.