Brian Barrington is a barrister and has worked as a lawyer in Dublin, Brussels and Washington. In March 1999 he became a special advisor to Seamus Mallon as Deputy First Minister of Northern Ireland and then to Mark Durkan in the same capacity. Upon the suspension of devolved government in October 2002 he continued to serve Mr. Durkan as party leader. Throughout all this time he advised on equality, human rights, policing, criminal justice, community relations, and constitutional and legal matters and participated in SDLP negotiating teams on these issues.

From May 2007, when devolved government was restored, to September of that year he served as a special adviser to Margaret Ritchie before returning to practice as a barrister in Dublin, where he specializes in child law, equality and human rights.