The whale was found off Oxley Beach in Port Macquarie about 10am on Friday.
The creature is believed to be only a week old and was found smashed against the rocks.
The NSW National Parks and Wildlife Service and the Australian Cetacean Rescue and Research Organization worked to save the whale’s life, but it sadly died on Friday afternoon.
Volunteers put wet blankets on the whale and used buckets to pour salt water over the creature, but it was too late.
The mother whale has not been seen surfacing in the area.
Humpback whales stay with their offspring for up to a year until they are ready to be alone.