The initiative has been co-ordinated by 18-year-olds Abbey James and Laura MacKay.
"We heard about the great work that the orphanage does there. But they don't have a lot of resources, and they don't get much funding, so we wanted to help," Laura said.
The orphanage struggles to provide enough food, let alone basics like nappies, baby milk formula, soap, toothbrushes and toothpaste, toilet paper, spoons or even clothes.
Abbey said the group of St Hilda's pupils had been raising funds since the beginning of the year to buy essential products for the children. Many goods had also been donated.
The items would be taken to Fiji in suitcases, and only a small amount of space in carry-on luggage would be used to carry the girls' personal bare necessities, such as a change of clothes and a toothbrush.
They would stay in backpacker accommodation, rather than at a resort, she said.
"Most people only see the resorts and not the poverty which exists on the other side.
"For us, the other side is going to be a pretty big shock. It will definitely be an eye-opener."
The team will be in Fiji from August 11 to 18.
