Officers arrested the 14-year-old as part of an investigation into the sexual assault of a girl next to a golfing green.
The girl – who is also a teenager – has alleged the boy hugged and kissed her against her will.
It is thought the victim and had been walking with the offender when he made unwanted advances towards the girl.
Police have revealed the girl was also inappropriately touched under her clothing.
“We are appealing to witnesses who saw anything suspicious in this area to come forward”
Detective Constable Carolyn Bailey of Aylesbury CID
The alleged incident is said to have taken place in a field adjacent to Aylesbury Park Golf Club at lunchtime on Saturday.
Officers confirmed a 14-year-old boy from Aylesbury was arrested on suspicion of sexual assault.
Detective Constable Carolyn Bailey of Aylesbury CID, said: “We are appealing to witnesses who saw anything suspicious in this area to come forward.
“Private CCTV may have captured the moments before and after the incident, so we would ask you check any footage from the area.”
Thames Valley Police tweeted: “Thames Valley Police is appealing for witnesses following a sexual assault in Aylesbury.
“It happened last Saturday in a field near to Eyre Close and Cooks Road.”
It is thought the schoolboy has been released under investigation.