John Naylor, the current chair of the Office of the Scottish Charity Regulator (OSCR), will retire in February 2011, with chief executive Jane Ryder also taking retirement later in the year.
Ryder was appointed by ministers in Scotland to establish OSCR in 2003. She was reappointed as its chief executive in 2006.
OSCR is advertising for a replacement for Naylor, who became the organisation's first chair in 2006. The chair will then appoint the new chief executive.
In a statement, Naylor said: "I leave with key policies and systems established so that my successor has a firm foundation on which to appoint a new chief executive."