Pc Adam Rushton was found guilty of five counts of misconduct in a public office and one count of obtaining personal data at Birmingham Crown Court today.
He was cleared of five other charges of misconduct in a public office and another charge of obtaining personal data.
The charges he was convicted of by the jury of nine men and two women relate to four different women.
The incidents took place between 2006 and 2012.
He was arrested in April 2013 and questioned about the matters.
The 37-year-old, of Newcastle- under -Lyme, is due to be sentenced at the court on May 1 and was given conditional bail until the hearing.
Deputy Chief Constable Nick Baker, from Staffordshire Police, said: "I would like toapologise to the victims, witnesses and their families who have suffered as a result of Rushton's actions.
"And they are thanked for their support, cooperation and understanding throughout this inquiry. Their bravery in giving evidence cannot be underestimated.
"Adam Rushton is a disgrace to the police service.
"He has brought shame on himself, his colleagues and Staffordshire Police.
"This was an astonishing breach of trust by an individual officer and he has badly let down vulnerable victims and their families.
"The public must be able to trust their police officers, and on this occasion they have
been let down.
"We made the decision that Rushton should be prosecuted as a police officer, and hope this sends out a very strong message - no matter who you are, and what
position you hold, if you commit crime you will be dealt with firmly and robustly.
"Once these matters came to light in 2013, a mandatory referral was made to the Independent Police Complaints Commission (IPCC) and a managed investigation
"As a result of this investigation more robust processes have been put in place to identify any such issues.
"As an organisation we are now more proactive than ever in identifying such risks
and taking immediate action against those concerned.
"I want to reassure the public of Staffordshire that lessons have been learnt from this matter and we will take robust action against anyone whose behaviour falls below the high standards expected.
"We are proud that the overwhelming majority of officers and staff members work hard and with integrity to serve the people of Staffordshire."