Wimbledon champion Maria Sharapova has been stalked in the past
Police officers have written to nearly a dozen potential stalkers warning them not to attend Wimbledon.
The Metropolitan Police has written to 11 known "fixated individuals", banning them from entering the venue.
Officers would not reveal which players were at risk but said Russian star Maria Sharapova and the Williams sisters had been stalked previously.
A member of one player's family has a restraining order barring them from attending the tournament, police said.
"There are a number of individuals well known to the police, the All England Club and the tennis authorities," said Supt Pete Dobson.
"They have been written to and banned from entering the club."
Police have also written to between 20 and 30 ticket touts who have attended past tournaments warning them to stay away.
A dispersal zone giving the police power to move on groups of two or more people acting anti-socially has also been put in place.
Under the Anti-social Behaviour Act 2003 anyone failing to move on could be liable to a three-month prison term or £2,000 fine.
This is the first time the powers have been used at a major sporting event.
"We are concerned about the high number of touts coming down causing harassment, alarm and distress," said a police spokesman.
"Having big burly blokes coming up to you at the Tube station trying to sell you tickets that could be lost, stolen or potentially forgeries is anti-social."