Directors of the UK's Office for National Statistics (ONS) also hold the title of National Statistician.
They are de facto Permanent Secretaries but do not use that title. As the ONS incorporated the OPCS, the Director also became the Registrar General for England and Wales. Following the implementation of the Statistics and Registration Service Act 2007, the General Register Office continues to be part of a ministerially-accountable department, becoming a part of the Identity & Passport Service in the Home Office and the post of Registrar-General is now held by its head.
Other duties 
In addition, the National Statistician is ex officio the Head of the UK Government Statistical Service (GSS), consisting of statisticians working in other departments and branches of government.
National Statisticians 
- The first Director of ONS was Professor Tim Holt. Subsequent Directors have had this additional title, the National Statistician.
- The second Director was Len Cook, who had previously held a similar post in New Zealand.
- He was succeeded by Karen Dunnell on 1 September 2005.
- Jil Matheson succeeded Dame Karen Dunnell on 1 September 2009
Current incumbent 
Jil Matheson became Director General for Statistics Delivery at the ONS in 2008 with responsibility for the delivery of all ONS statistical operations and outputs, and for the development of the ONS’ statistical portfolio in consultation with users. She is a Fellow of the Academy of Learned Societies in Social Science (2001), and she is also a Fellow of the Royal Statistical Society and a member of the Social Research Association.
Since the inception of the UK Statistics Authority, the National Statistician is also its chief executive.