The massacre occurred on Saturday after the suspect allegedly hit and killed them with a vehicle between 10:30 p.m. and 11:30 p.m., according to a press release by the New South Wales Police Force.
Police began receiving reports of multiple dead kangaroos on the road the next morning, police said.
Photos published by local media show multiple kangaroos lying on a residential street.
The suspect was arrested Tuesday afternoon and charged with torture, beating and causing the of death of an animal, police said.
Bega Valley Officer in Charge, Inspector Peter Volf, said in a statement that acts of cruelty toward animals will not be tolerated.
"We take incidents such as these very seriously and anyone who engages in activities such as these will face the full brunt of the law," Volf said.
The teen was granted conditional bail and will appear in court Nov. 26, police said.