The survey from the Information Commissioner's Office (ICO), which took in responses from more than 1200 people, also found that 96% of individuals surveyed are concerned that organisations do not keep their details secure.
In addition, a further 60% believe that they have lost control of the way their personal information is collected and processed.
To help online users understand how to surf safely, the ICO has relaunched its Personal Information Toolkit, which includes tips on how to protect personal details online as well as setting out people’s rights to access and correct the information that is held about them.
The previous version of the toolkit, says the ICO, has been requested by over 100,000 members of the public to date.
The UK's information commissioner, Christopher Graham, said that it has never been more important to protect your personal information.
"Whether you're surfing the net, shopping online or signing up to social networking sites, it's crucial that people are thinking about how their information might be used", he said.
"From employers looking up potential employees on Facebook to cybercriminals hacking into unsecured WiFi networks, not protecting your personal information can cause serious harm and distress", he added.
International data protection day, he went on to say, is about motivating people to regain control of their right to privacy. I hope people of all ages across the UK will do just that.
Commenting on the ICO's survey, Richard Turner, chief executive with Clearswift, said that the agency is right to say there is a real issue when it comes to people understanding how to protect themselves online.
"And it's not just about personal data, the knowledge gap is a huge issue within businesses", he said, adding that it is not surprising that so many people feel their data is not in safe hands with businesses, as his company's research has shown that a third of those surveyed had not received any training on IT security since joining their firm.
"Many businesses still have such an outdated stop-and-block approach to security that it is frustrating for employees, and they go to great lengths to get around overly intrusive security. Not good", he said.
"Living our lives online and often in the workplace, it is more vital than ever before that people are better educated when it comes to IT security", he added.