He was chief executive of Barnardo's for 21 years, succeeding Mary Joynson, and was awarded a knighthood for his services to children in 2005. He has served on public inquiries into child abuse in children's homes and is involved in the governance and management of various charities. Singleton is also chairman of Perennial Gardeners Royal Benevolent Society, one of the UK's oldest charities which was created in 1839 helping horticulturists facing times of difficulty. Singleton is also an accredited mediator. Singleton was universally seen as a balanced and liberal spokesman for children's rights. Indeed, the only significant public criticisms made of him as a professional for the bulk of his career, prior to 2009, were accusations in 2003 that as chief executive of Barnardo's he had supported emotionally manipulative advertising campaigns used to raise the charity's profile. In this case the UK advertising standards authority found decisively in Singleton's and Barnardo's favour.
Singleton has been chairing the ISA since 2007. The ISA was set up to deliver its responsibilities under the Safeguarding Vulnerable Groups Act (2006) and as part of the Vetting and Barring Scheme (VBS). It makes barring decisions on those people referred to it (usually from employers) following harm or the risk of harm to a child or vulnerable adult. It has the legal powers to place or remove people from both of its barred lists (for Children and Adults). In March 2009 the Government appointed Singleton Chief Adviser on the Safety of Children, where his responsibilities included advising the Government on strategic priorities and reporting annually to Parliament on safeguarding progress. He stood down from the role in June 2010.
In Autumn 2009 anger erupted in the press against the VBS, which Singleton chairs and which was at the time due to require a phased introduction of all people working or volunteering with children and vulnerable adults to become ISA-Registered. The most vociferous articles opposing the VBS, in 2009, were in the Daily Telegraph, although these were then expanded upon by the Today, programme. Singleton responded to these by pointing out that many of the parliamentarians who were criticising the scheme had actually voted for it.
In his role as Chief Advisor, Sir Roger was asked by Ed Balls the then Children's Minister to undertake a 'check' on the Government's definition of 'regulated activity' – the guidance which would define whether someone needed to be registered under the Scheme. His recommendations were published in December 2009 – "Drawing the line" and were accepted by the Government. His proposals were projected to reduce the number of people due to be ISA-Registered by approximately 2million. In 2010, the Coalition Government initially announced a delay to registration and then undertook a review of the VBS, which proposed a series of amendments to the Scheme including the abolition of the need to register. The proposals are currently going through Parliament in The Protection of Freedoms Bill – to which Singleton was asked to give evidence.
Following what have been seen as widely welcomed changes, the Independent Safeguarding Authority continues to exist although it has been amalgamated with the Criminal Records Bureau. The ISA retains the role of maintaining a list of people barred from working with children and vulnerable adults. Singleton's continued defence of the re-structured ISA continues to draw criticism as the ISA is still perceived by many as being authoritarian and structured in an unethical way with high profile journalists such as Josie Appleton continuing to protest against it via the 'Manifesto Club' which she chairs.  This has been seen by some as having damaged his credibility severely. This was particularly demonstrated by successful legal cases taken by the Royal College of Nursing against the ISA in 2010. The Royal College of Nursing alongside other organisations continues to campaign for the ISA to include a hearing within the ISA barring process, for the ISA to have minimal standards of evidence and to have flexible sanctions, indeed that the ISA should use the word 'sanction' when describing the barring process. The ISA under Singleton's leadership continues to resist these changes. To this extent he has become probably the most public figure representing a perceived authoritarian conservative stance within Britain's current child protection debate.
- "Roger SINGLETON – Personal Appointments (free information from Companies House)". Government of the United Kingdom. Retrieved 12 May 2016.
- John Carvel. "Barnardo's ad provokes storm of protest | Society". The Guardian. Retrieved 12 May 2016.
- "Manifesto Club". Manifesto Club. Retrieved 12 May 2016.
- Merrifield, Nicola. "Resources for the nursing profession". Nursing Times. Retrieved 12 May 2016.
- "Profiles of Honorary Graduates". bath.ac.uk. Retrieved 13 October 2017.