The Northland Regional Council's chief executive, Malcolm Nicolson, said the latest directors were chosen from a pool of a dozen hopefuls after a lengthy appointment process based on the particular skills they brought to the board.
He is also pleased the new appointees have strong links to the region.
"Karleen and Sarah round out a team which already boasts a huge and varied experience locally, nationally and internationally and I'm thrilled to see a board of such high calibre in place."
The two new appointees will be paid $13,125 each annually, with the length of their appointments to be determined shortly.
Mr Nicolson says a big part of the directors' roles will be to give effect to the regional council's objective of building a business-friendly environment.
Ms Everitt (Te Aupouri/Ngaphui) lives at Paihia and her company is based there. Ms Petersen was educated in the Far North and maintains interest in a family farm and businesses in and around Kaikohe.
The other Northland Inc directors are Mr Mitten, David Caselli, James Parsons and Russell Shaw.