The ban comes following an investigation into financial irregularities by the Insolvency Service.
The ruling relates to payments totalling £347,000 made by Cardiff to Ridsdale between May 2007 and March 2009 during his spell as their chairman.
The monies should have been directed to the 60-year-old's WH Sports Group (WHSG) consultancy service.
WHSG was liquidated in April 2009 with liabilities of £478,698, including significant tax debts of £442, 353 owed to HM Revenue and Customs.
Ridsdale's wife Sophie served as a co-director a WHSG and has been banned until April 2016.
Claire Entwistle, director of company investigations north at the Insolvency Service, said: "As someone who has had many directorships, Mr Ridsdale ought to be aware of the responsibilities that come with such a position.
"The protection of limited liability is available to those who comply with their obligations as company directors.
"If those obligations are ignored, the protection will be withdrawn, as Mr Ridsdale has found to his cost."
Ridsdale's role as chairman of football at Preston will not be affected and following the verdict he issued his own statement through the club.
The former Leeds and Plymouth chief said: "I can confirm that I have agreed a voluntary undertaking not to act as a company director as a result of ongoing issues with a personal matter which occurred in 2009.
"I am currently undertaking a role of 'Chairman of Football' at Preston North End but am not a director nor at any time have I sought to be one."