The London-based duo oversee a policy and PA team that is around 25-strong and includes offices in Wales and Northern Ireland.
Sutton's hire comes as the NSPCC lobbies the Government on its Working Together To Safeguard Children consultation, which outlines new structures for welfare ahead of future legislation.
The PA team is also working on the NSPCC's high-profile Full Stop campaign to stop child cruelty, launched in March 1999. This incorporates all of the NSPCC's campaigning, lobbying, communication and public education activities.
The most recent initiative, Talk 'til it Stops, was launched last month, with ads aiming to raise awareness of Full Stop Week, which ran in early October.
As joint head of policy and public affairs, the pair replace Liz Atkins, who joined the National Housing Federation last year (PRWeek, 8 October 2004).
Vince Muspratt, acting head of public affairs after Atkins' exit, left last week to become Norfolk County Council investing in communities manager.
Cronin and Sutton report to NSPCC director of public policy Philip Noyes.
Their remit is UK-wide, with another team member – EU adviser Tara Hopkins – based in London and travelling to Brussels three times a month.
Sutton has been replaced by Hans Lind as acting head of Save the Children's Brussels office. The post will be taken up permanently by Olivia Lind Haldorffon, who is on maternity leave until January.