Roberts, press and parliamentary officer for the NI Federation of Small Businesses, replaces Morrow Communications consultant Peter Conway after an uncontested election.
Roberts said that despite the latest suspension of the Northern Ireland assembly, which took effect last week, he was 'optimistic' that devolution would be restored within six months. He said the 'policy agenda of our members is still very much present'.
NIGAG was launched in March 2000 to assist public affairs practitioners by organising networking events and best-practice seminars.
Roberts said he would focus on improving NIGAG's work on lobbying in Westminster and Brussels during his year as chairman.
He said focusing on the policy agenda surrounding the next year's elections to the assembly would also be a priority.
NIGAG's founding chairman was Conor McGrath, a lecturer in political communications and public affairs at the University of Ulster. When NIGAG launched, Roberts was vice-chair.
Roberts also works part-time as producer of Belfast City Beat 96.7 FM's arts and culture show, Week In, Week Out.