Mr Cull was one of two candidates for the role of LGNZ president, but in a noon vote at the group's annual meeting in Auckland yesterday he triumphed over Nelson Mayor Rachel Reese.
He takes over from Hastings mayor and now National Party candidate Lawrence Yule, who has completed the three three-year terms allowed under LGNZ rules.
Mr Cull will now have to juggle his mayoral and presidential roles.
The organisation represents the national interests of New Zealand's 78 councils, providing advocacy and policy services, business support, advice and training.
Mr Cull has been LGNZ's vice-president and chairman of its metro sector.
He said in a statement late yesterday New Zealand's councils had their own unique issues ''but are also united by many common challenges which need strong advocacy''.
''We face infrastructural funding challenges, and challenges from climate change effects.
''We face challenges around water, its provision, disposal, quality and allocation.
''We face capacity constraints whether we are high or low growth councils, but especially rural and provincial councils.''
Mr Cull said it was important local government asserted its role, independent of the Government, by developing a vision with, and for its communities.
His new role would require he manage his time, rather than sacrifice responsibility of either role, he said.
As president, he would work to increase recognition of local government's mandate and the right of local government not to have its views on local issues ''totally overruled'' by central government.
The presidential role would last three years, about eight months longer than his current mayoralty.
Mr Cull has yet to decide if he would stand for mayor again.
