Auckland will replace Michael Pelosi, who stayed on as a consultant at the firm after stepping down from the role at the end of the year. Pelosi has been at Northcliffe for 22 years.
Pelosi's deputy, Alex Leys, is also retiring after 28-years with the media company.
Grant joined Associated in 2005 from Capital Radio, where she was commercial chief. She was previously marketing director at Metro and also worked at The Scotsman and Newsquest.
At Associated, Grant's main task has been to gain a third source of revenue beyond cover price and advertising. She is also in charge of Associated's creative services and research departments.
In an email to staff, Kevin Beatty group managing director Associated Newspapers, said Pelosi and Leys had made a "huge contribution" to the success of the company.