The incidents took place in Wolverton in April and July this year.
The first incident occurred on Friday, 22 April in an alleyway between Thames Street and Windsor Street.
The victim, a 59-year-old woman, was approached by a teenage boy who touched her inappropriately.
The second offence occurred on Sunday (8/7) in Church Street.
The victim, a 47-year-old woman, was approached by a teenage boy who touched her inappropriately.
The third offence occurred on Monday (9/7) in Windsor Street.
The victim, a 23-year-old woman, was approached by a teenage boy who touched her inappropriately.
Officers believe the offences are linked and that the same person is responsible for each incident.
The offender is an Asian teenage boy, aged between 13 and 18. He is about 5ft 6ins tall, with a thin build, black hair and is clean shaven.
Investigating officer, Detective Constable Laura Herrington, based at Bletchley police station, said: “I would like to speak to anyone who witnessed any of these incidents, or who recognises the description of the offender.
“Detectives have been working to identify and locate the offender since April and we are continuing our investigation and appealing to the public for information.
“If you have any details at all which you think could help our investigation, please call the Thames Valley Police non-emergency number on 101.”