Callan, County Kilkenny
On 30 March 2007 Shefflin married Deirdre O'Sullivan, a native of Callan, County Kilkenny and a camogie player of note in her own right. Just over a year later in April 2008 the Shefflins celebrated the birth of their first child, a daughter named Sadhbh. On 30 October 2009 Henry Michael Shefflin, the couple's second child and first son, was born. A third child, Siún, was born in March 2011, while the Shefflin's youngest boy, Freddie, was born in April 2014.