Jonathan Nadji was born at Bagot Aboriginal Reserve in Darwin. His father is Bill Neidjie (q.v.). Nadji's clan is Bunitj.
He lived on Croker Island from the age of three but when he was eight years of age, his family moved to Malay Bay and then to Murganella. Nadji was the only one interested school, so his father encouraged him to continue his education. While at school, he excelled in sports, travelling interstate representing the Territory in competitions. After High School the South Alice Springs Club offered him a space on the football team with opportunities for a job in the area. He did not stay in Alice Springs for long, because his family called him and told him of a job coming up in his community. For eight months he worked as a bus driver, before he found work as an Indigenous trainee ranger at Kakadu National Park. He was given accreditation for his cultural knowledge but had to learn the administrative side of ranger work. In 1987 he graduated from his ranger traineeship.
In 1990, he was elected Chairman of Djabulukgu Association. Nadji has a strong commitment to keeping his culture living within his community and sharing it with those who come to visit his traditional lands.