It follows an incident on the Green, Nursteed Road on January 10 where a man in his 20s was attacked with a wooden bat. The victim suffered a deep cut to his head, missing teeth and a suspected fractured arm.
When appearing at Swindon Magistrates Court on April 11 he also pleaded guilty to possession of an air weapon and assaulting an emergency worker on 8 April. He was given a four-month Detention and Training Order.
The 15-year-old also pleaded guilty to the criminal damage of a police cell door.
Sgt Luke Atkinson for Devizes said: “This is completely disgraceful and shocking behaviour that simply will not be tolerated in our community.
We have seen an increase in youth related crime recently, and we would encourage anyone who sees anything suspicious to contact us immediately. Our officers will always respond swiftly and robustly to reports of this nature.”