The severance package, which has shocked some staff and taxpayer groups, was signed off by the Scottish Government and amounts to nearly three times her annual salary.
The government agency that manages some of Scotland's most popular historic attractions said in June 2012 that Ruth Parsons was retiring from the agency and would leave in August the same year.
Its financial statements reveal that Ms Parsons received "compensation for loss of office" in the region of £290,000.
Ms Parsons, 51, who had a 30-year career as a civil servant with the UK and Scottish Government, accrued pension scheme benefits, seven months after she had left, making her eligible for around £35,000 a year plus a £105,000 lump sum on retirement, the statements add.
Appointed in 2009, her time as chief executive was marred by a staff survey in October 2011, which revealed claims by staff that they faced harassment at work.
The wellbeing study of Historic Scotland's 1100 staff at the time found that 53 - 5% - reported some form of bullying. Five said they were often victimised and two felt they were always bullied.
While the organisation says no formal complaints were lodged, a spate of departures by experienced senior managers after her appointment included Doreen Grove, head of understanding and access, Peter Bromley, director of properties in care, Malcolm Cooper, the agency's chief inspector, who left in 2011 due to a stress-related illness, and Pat Connor, head of communications.
Ms Parsons, who remains deputy director of the Strathclyde Inter-national Public Policy Institute at Strathclyde University, has always strongly denied allegations of discontent within the organisation, including accusations of "bullying" levelled at her personally.
Robert Oxley, campaign director of the TaxPayers' Alliance campaign group, said: "This is an extraordinary payoff that raises huge questions over who approved it and why. Given the record of Historic Scotland under Ruth Parsons's leadership, many will question why she has been handed a penny given that she resigned.
"Taxpayers must be assured that they haven't paid a huge bill to ease Parsons out quietly."
The development comes days after the Reform Scotland think tank survey revealed that more than one in three quango bosses are paid at least as much as First Minister Alex Salmond.
Details revealed in Historic Scotland financial papers show that its former CEO left under the Cabinet Office-approved Civil Service early severance terms and that the payoff came from the Scottish Government "as Ms Parsons was on loan to Historic Scotland from the Scottish Government at the time of her departure".
According to the Scottish Govern-ment severance terms, compensation is not normally payable "when someone resigns voluntarily outwith any existing (and approved) scheme" of compensation. Ministerial clearance must also be obtained as and when appropriate, "including in relation to any potentially high-profile cases".
Scottish Government rules state: "Compensation should not be offered in order to avoid normal management procedures, disciplinary action, unwelcome publicity or reputational damage. And even if the cost of defeating an appeal would exceed the cost of a particular settlement it may still be desirable to take the case to formal proceedings."
Four months after leaving Historic Scotland, Ms Parsons became executive director of Edinburgh-based non-profit heritage firm CyArk Europe. Prior to her arrival, CyArk estab-lished a partnership with Historic Scotland during Ms Parsons' time in charge and the Glasgow School of Art to deliver the Scottish Government funded Scottish Ten project.
The ambitious five-year scheme involved the use of cutting edge technology to create digital models of Scotland's five Unesco designated World Heritage Sites.
Before taking the helm at Historic Scotland, Ms Parsons was the Scottish Government Director for Local Government, the Third Sector and Public Service Reform for three years.
She joined the Scottish Government after 21 years with HM Customs and Excise, where she led a major transformation programme, developing a new indirect tax strategy for dealing with the UK's largest businesses.
She was responsible for assuring the collection of VAT, Excise and Customs revenues for more than 200 of the largest businesses in Scotland, Northern Ireland and the North of England.
A spokesman for Historic Scotland said: "Ruth Parsons was on assignment from the Scottish Government to Historic Scotland as chief executive.
"She was a civil servant for 30 years and, along with a number of other senior civil servants, applied for and was granted early exit under a general scheme which was operating at that time for all civil servants within the Scottish Government.
"The exit package for Ruth Parsons was funded by the Scottish Government and not from Historic Scotland budgets.
"In line with her terms and conditions of employ-ment the level of payment was what she was entitled to on her departure and reflected the terms which applied to others."